diff --git a/src/com/android/browser/DataController.java b/src/com/android/browser/DataController.java
index a56fce8..909c2a3 100644
--- a/src/com/android/browser/DataController.java
+++ b/src/com/android/browser/DataController.java
@@ -23,12 +23,17 @@
 import android.content.Context;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteException;
+import android.graphics.Bitmap;
+import android.net.Uri;
 import android.os.Handler;
 import android.os.Message;
 import android.provider.BrowserContract;
 import android.provider.BrowserContract.History;
 import android.util.Log;
 
+import com.android.browser.provider.BrowserProvider2.Thumbnails;
+
+import java.nio.ByteBuffer;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 
@@ -37,12 +42,16 @@
     // Message IDs
     private static final int HISTORY_UPDATE_VISITED = 100;
     private static final int HISTORY_UPDATE_TITLE = 101;
-    public static final int QUERY_URL_IS_BOOKMARK = 200;
+    private static final int QUERY_URL_IS_BOOKMARK = 200;
+    private static final int TAB_LOAD_THUMBNAIL = 201;
+    private static final int TAB_SAVE_THUMBNAIL = 202;
+    private static final int TAB_DELETE_THUMBNAIL = 203;
     private static DataController sInstance;
 
     private Context mContext;
     private DataControllerHandler mDataHandler;
     private Handler mCbHandler; // To respond on the UI thread
+    private ByteBuffer mBuffer; // to capture thumbnails
 
     /* package */ static interface OnQueryUrlIsBookmark {
         void onQueryUrlIsBookmark(String url, boolean isBookmark);
@@ -72,7 +81,6 @@
     private DataController(Context c) {
         mContext = c.getApplicationContext();
         mDataHandler = new DataControllerHandler();
-        mDataHandler.setDaemon(true);
         mDataHandler.start();
         mCbHandler = new Handler() {
             @Override
@@ -108,15 +116,31 @@
         mDataHandler.sendMessage(QUERY_URL_IS_BOOKMARK, url.trim(), replyTo);
     }
 
+    public void loadThumbnail(Tab tab) {
+        mDataHandler.sendMessage(TAB_LOAD_THUMBNAIL, tab);
+    }
+
+    public void deleteThumbnail(Tab tab) {
+        mDataHandler.sendMessage(TAB_DELETE_THUMBNAIL, tab.getId());
+    }
+
+    public void saveThumbnail(Tab tab) {
+        mDataHandler.sendMessage(TAB_SAVE_THUMBNAIL, tab);
+    }
+
     // The standard Handler and Message classes don't allow the queue manipulation
     // we want (such as peeking). So we use our own queue.
     class DataControllerHandler extends Thread {
         private BlockingQueue<DCMessage> mMessageQueue
                 = new LinkedBlockingQueue<DCMessage>();
 
+        public DataControllerHandler() {
+            super("DataControllerHandler");
+        }
+
         @Override
         public void run() {
-            super.run();
+            setPriority(Thread.MIN_PRIORITY);
             while (true) {
                 try {
                     handleMessage(mMessageQueue.take());
@@ -152,6 +176,67 @@
                 //       multiple callbacks querying the same URL)
                 doQueryBookmarkStatus((String) msg.obj, msg.replyTo);
                 break;
+            case TAB_LOAD_THUMBNAIL:
+                doLoadThumbnail((Tab) msg.obj);
+                break;
+            case TAB_DELETE_THUMBNAIL:
+                ContentResolver cr = mContext.getContentResolver();
+                try {
+                    cr.delete(ContentUris.withAppendedId(
+                            Thumbnails.CONTENT_URI, (Long)msg.obj),
+                            null, null);
+                } catch (Throwable t) {}
+                break;
+            case TAB_SAVE_THUMBNAIL:
+                doSaveThumbnail((Tab)msg.obj);
+                break;
+            }
+        }
+
+        private byte[] getCaptureBlob(Tab tab) {
+            synchronized (tab) {
+                Bitmap capture = tab.getScreenshot();
+                if (capture == null) {
+                    return null;
+                }
+                if (mBuffer == null || mBuffer.limit() < capture.getByteCount()) {
+                    mBuffer = ByteBuffer.allocate(capture.getByteCount());
+                }
+                capture.copyPixelsToBuffer(mBuffer);
+                mBuffer.rewind();
+                return mBuffer.array();
+            }
+        }
+
+        private void doSaveThumbnail(Tab tab) {
+            byte[] blob = getCaptureBlob(tab);
+            if (blob == null) {
+                return;
+            }
+            ContentResolver cr = mContext.getContentResolver();
+            ContentValues values = new ContentValues();
+            values.put(Thumbnails._ID, tab.getId());
+            values.put(Thumbnails.THUMBNAIL, blob);
+            cr.insert(Thumbnails.CONTENT_URI, values);
+        }
+
+        private void doLoadThumbnail(Tab tab) {
+            ContentResolver cr = mContext.getContentResolver();
+            Cursor c = null;
+            try {
+                Uri uri = ContentUris.withAppendedId(Thumbnails.CONTENT_URI, tab.getId());
+                c = cr.query(uri, new String[] {Thumbnails._ID,
+                        Thumbnails.THUMBNAIL}, null, null, null);
+                if (c.moveToFirst()) {
+                    byte[] data = c.getBlob(1);
+                    if (data != null && data.length > 0) {
+                        tab.updateCaptureFromBlob(data);
+                    }
+                }
+            } finally {
+                if (c != null) {
+                    c.close();
+                }
             }
         }
 
@@ -184,7 +269,6 @@
         }
 
         private void doQueryBookmarkStatus(String url, Object replyTo) {
-            ContentResolver cr = mContext.getContentResolver();
             // Check to see if the site is bookmarked
             Cursor cursor = null;
             boolean isBookmark = false;
diff --git a/src/com/android/browser/PhoneUi.java b/src/com/android/browser/PhoneUi.java
index ffcaaf8..a13eca3 100644
--- a/src/com/android/browser/PhoneUi.java
+++ b/src/com/android/browser/PhoneUi.java
@@ -529,12 +529,14 @@
                 if (mTitleBarBitmap == null
                         || mTitleBarBitmap.getWidth() != tbar.getWidth()
                         || mTitleBarBitmap.getHeight() != tbar.getEmbeddedHeight()) {
-                    mTitleBarBitmap = Bitmap.createBitmap(tbar.getWidth(),
-                            tbar.getEmbeddedHeight(), Bitmap.Config.RGB_565);
+                    mTitleBarBitmap = safeCreateBitmap(tbar.getWidth(),
+                            tbar.getEmbeddedHeight());
                 }
-                Canvas c = new Canvas(mTitleBarBitmap);
-                tbar.draw(c);
-                c.setBitmap(null);
+                if (mTitleBarBitmap != null) {
+                    Canvas c = new Canvas(mTitleBarBitmap);
+                    tbar.draw(c);
+                    c.setBitmap(null);
+                }
             } else {
                 mTitleBarBitmap = null;
             }
@@ -544,18 +546,28 @@
             if (mContentBitmap == null
                     || mContentBitmap.getWidth() != web.getWidth()
                     || mContentBitmap.getHeight() != h) {
-                mContentBitmap = Bitmap.createBitmap(web.getWidth(), h,
-                        Bitmap.Config.RGB_565);
+                mContentBitmap = safeCreateBitmap(web.getWidth(), h);
             }
-            Canvas c = new Canvas(mContentBitmap);
-            int tx = web.getScrollX();
-            int ty = web.getScrollY();
-            c.translate(-tx, -ty - tbar.getEmbeddedHeight());
-            web.draw(c);
-            c.setBitmap(null);
+            if (mContentBitmap != null) {
+                Canvas c = new Canvas(mContentBitmap);
+                int tx = web.getScrollX();
+                int ty = web.getScrollY();
+                c.translate(-tx, -ty - tbar.getEmbeddedHeight());
+                web.draw(c);
+                c.setBitmap(null);
+            }
             mContent.setImageBitmap(mContentBitmap);
         }
 
+        private Bitmap safeCreateBitmap(int width, int height) {
+            if (width <= 0 || height <= 0) {
+                Log.w(LOGTAG, "safeCreateBitmap failed! width: " + width
+                        + ", height: " + height);
+                return null;
+            }
+            return Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
+        }
+
         public void set(Bitmap image) {
             mTitle.setVisibility(View.GONE);
             mContent.setImageBitmap(image);
diff --git a/src/com/android/browser/Tab.java b/src/com/android/browser/Tab.java
index 8a3febe..dd97960 100644
--- a/src/com/android/browser/Tab.java
+++ b/src/com/android/browser/Tab.java
@@ -20,13 +20,11 @@
 import android.app.AlertDialog;
 import android.app.SearchManager;
 import android.content.ContentResolver;
-import android.content.ContentUris;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.DialogInterface.OnCancelListener;
 import android.content.Intent;
-import android.database.Cursor;
 import android.graphics.Bitmap;
 import android.graphics.Bitmap.CompressFormat;
 import android.graphics.BitmapFactory;
@@ -73,7 +71,6 @@
 
 import com.android.browser.TabControl.OnThumbnailUpdatedListener;
 import com.android.browser.homepages.HomeProvider;
-import com.android.browser.provider.BrowserProvider2.Thumbnails;
 import com.android.browser.provider.SnapshotProvider.Snapshots;
 import com.android.common.speech.LoggingEvents;
 
@@ -2013,7 +2010,7 @@
         mCurrentState.mTitle = title;
         synchronized (Tab.this) {
             if (mCapture != null) {
-                BackgroundHandler.execute(mLoadThumbnail);
+                DataController.getInstance(mContext).loadThumbnail(this);
             }
         }
     }
@@ -2093,6 +2090,9 @@
 
     protected void capture() {
         if (mMainView == null || mCapture == null) return;
+        if (mMainView.getContentWidth() <= 0 || mMainView.getContentHeight() <= 0) {
+            return;
+        }
         Canvas c = new Canvas(mCapture);
         final int left = mMainView.getScrollX();
         final int top = mMainView.getScrollY() + mMainView.getVisibleTitleHeight();
@@ -2170,14 +2170,14 @@
     }
 
     protected void persistThumbnail() {
-        BackgroundHandler.execute(mSaveThumbnail);
+        DataController.getInstance(mContext).saveThumbnail(this);
     }
 
     protected void deleteThumbnail() {
-        BackgroundHandler.execute(mDeleteThumbnail);
+        DataController.getInstance(mContext).deleteThumbnail(this);
     }
 
-    private void updateCaptureFromBlob(byte[] blob) {
+    void updateCaptureFromBlob(byte[] blob) {
         synchronized (Tab.this) {
             if (mCapture == null) {
                 return;
@@ -2194,76 +2194,6 @@
         }
     }
 
-    private static final ThreadLocal<ByteBuffer> sBuffer = new ThreadLocal<ByteBuffer>();
-
-    private byte[] getCaptureBlob() {
-        synchronized (Tab.this) {
-            if (mCapture == null) {
-                return null;
-            }
-            ByteBuffer buffer = sBuffer.get();
-            if (buffer == null || buffer.limit() < mCapture.getByteCount()) {
-                buffer = ByteBuffer.allocate(mCapture.getByteCount());
-                sBuffer.set(buffer);
-            }
-            mCapture.copyPixelsToBuffer(buffer);
-            buffer.rewind();
-            return buffer.array();
-        }
-    }
-
-    private Runnable mSaveThumbnail = new Runnable() {
-
-        @Override
-        public void run() {
-            byte[] blob = getCaptureBlob();
-            if (blob == null) {
-                return;
-            }
-            ContentResolver cr = mContext.getContentResolver();
-            ContentValues values = new ContentValues();
-            values.put(Thumbnails._ID, mId);
-            values.put(Thumbnails.THUMBNAIL, blob);
-            cr.insert(Thumbnails.CONTENT_URI, values);
-        }
-    };
-
-    private Runnable mDeleteThumbnail = new Runnable() {
-
-        @Override
-        public void run() {
-            ContentResolver cr = mContext.getContentResolver();
-            try {
-                cr.delete(ContentUris.withAppendedId(Thumbnails.CONTENT_URI, mId),
-                        null, null);
-            } catch (Throwable t) {}
-        }
-    };
-
-    private Runnable mLoadThumbnail = new Runnable() {
-
-        @Override
-        public void run() {
-            ContentResolver cr = mContext.getContentResolver();
-            Cursor c = null;
-            try {
-                Uri uri = ContentUris.withAppendedId(Thumbnails.CONTENT_URI, mId);
-                c = cr.query(uri, new String[] {Thumbnails._ID,
-                        Thumbnails.THUMBNAIL}, null, null, null);
-                if (c.moveToFirst()) {
-                    byte[] data = c.getBlob(1);
-                    if (data != null && data.length > 0) {
-                        updateCaptureFromBlob(data);
-                    }
-                }
-            } finally {
-                if (c != null) {
-                    c.close();
-                }
-            }
-        }
-    };
-
     @Override
     public String toString() {
         StringBuilder builder = new StringBuilder(100);
diff --git a/src/com/android/browser/UrlBarAutoShowManager.java b/src/com/android/browser/UrlBarAutoShowManager.java
index f1bbe7f..294115e 100644
--- a/src/com/android/browser/UrlBarAutoShowManager.java
+++ b/src/com/android/browser/UrlBarAutoShowManager.java
@@ -46,6 +46,7 @@
     private boolean mHasTriggered;
     private long mLastScrollTime;
     private long mTriggeredTime;
+    private boolean mIsScrolling;
 
     public UrlBarAutoShowManager(BaseUi ui) {
         mUi = ui;
@@ -71,6 +72,7 @@
     public void onScrollChanged(int l, int t, int oldl, int oldt) {
         mLastScrollTime = SystemClock.uptimeMillis();
         if (t != oldt) {
+            mIsScrolling = true;
             if (t != 0) {
                 // If it is showing, extend it
                 if (mUi.isTitleBarShowing()) {
@@ -88,6 +90,7 @@
     void stopTracking() {
         if (mIsTracking) {
             mIsTracking = false;
+            mIsScrolling = false;
             if (mUi.isTitleBarShowing()) {
                 mUi.showTitleBarForDuration();
             }
@@ -124,7 +127,8 @@
                     float angle = (float) Math.atan2(ady, adx);
                     if (dy > mSlop && angle > V_TRIGGER_ANGLE
                             && !mUi.isTitleBarShowing()
-                            && web.getVisibleTitleHeight() == 0) {
+                            && (web.getVisibleTitleHeight() == 0
+                            || (!mIsScrolling && web.getScrollY() > 0))) {
                         mTriggeredTime = SystemClock.uptimeMillis();
                         mUi.showTitleBar();
                     }