--- a/layout/generic/nsGfxScrollFrame.cpp
+++ b/layout/generic/nsGfxScrollFrame.cpp
@@ -2633,69 +2633,49 @@ nsXULScrollFrame::AddRemoveScrollbar(PRB
    return PR_FALSE;
 }
 
 void
 nsXULScrollFrame::LayoutScrollArea(nsBoxLayoutState& aState,
                                    const nsPoint& aScrollPosition)
 {
   PRUint32 oldflags = aState.LayoutFlags();
-  nsRect childRect = nsRect(nsPoint(0, 0),
+  nsRect childRect = nsRect(mInner.mScrollPort.TopLeft() - aScrollPosition,
                             mInner.mScrollPort.Size());
   PRInt32 flags = NS_FRAME_NO_MOVE_VIEW;
 
   nsRect originalRect = mInner.mScrolledFrame->GetRect();
   nsRect originalVisOverflow = mInner.mScrolledFrame->GetVisualOverflowRect();
 
   nsSize minSize = mInner.mScrolledFrame->GetMinSize(aState);
   
   if (minSize.height > childRect.height)
     childRect.height = minSize.height;
   
   if (minSize.width > childRect.width)
     childRect.width = minSize.width;
 
   aState.SetLayoutFlags(flags);
-  mInner.mScrolledFrame->SetBounds(aState, childRect);
+  ClampAndSetBounds(aState, childRect, aScrollPosition);
   mInner.mScrolledFrame->Layout(aState);
 
   childRect = mInner.mScrolledFrame->GetRect();
 
   if (childRect.width < mInner.mScrollPort.width ||
       childRect.height < mInner.mScrollPort.height)
   {
     childRect.width = NS_MAX(childRect.width, mInner.mScrollPort.width);
     childRect.height = NS_MAX(childRect.height, mInner.mScrollPort.height);
 
     // remove overflow areas when we update the bounds,
     // because we've already accounted for it
     // REVIEW: Have we accounted for both?
-    mInner.mScrolledFrame->SetBounds(aState, childRect, PR_TRUE);
+    ClampAndSetBounds(aState, childRect, aScrollPosition, PR_TRUE);
   }
 
-  /*
-   * After layout, restore the original position of the frame relative to the
-   * scroll port.
-   *
-   * In the LTR case, restore the original physical position (top left).
-   *
-   * In the RTL case, restore the original logical position (top right), then
-   * subtract the current width to find the physical position.
-   * This can break the invariant that the scroll position is a multiple of
-   * device pixels, so round off the result to the nearest device pixel.
-   */
-  if (mInner.IsLTR())
-    childRect.x = mInner.mScrollPort.x - aScrollPosition.x;
-  else {
-    childRect.x = PresContext()->RoundAppUnitsToNearestDevPixels(
-             mInner.mScrollPort.XMost() - aScrollPosition.x - childRect.width);
-  }
-  childRect.y = mInner.mScrollPort.y - aScrollPosition.y;
-  mInner.mScrolledFrame->SetBounds(aState, childRect);
-
   nsRect finalRect = mInner.mScrolledFrame->GetRect();
   nsRect finalVisOverflow = mInner.mScrolledFrame->GetVisualOverflowRect();
   // The position of the scrolled frame shouldn't change, but if it does or
   // the position of the overflow rect changes just invalidate both the old
   // and new overflow rect.
   if (originalRect.TopLeft() != finalRect.TopLeft() ||
       originalVisOverflow.TopLeft() != finalVisOverflow.TopLeft())
   {

--- a/layout/generic/nsGfxScrollFrame.h
+++ b/layout/generic/nsGfxScrollFrame.h
@@ -753,14 +753,31 @@ public:
 #ifdef NS_DEBUG
   NS_IMETHOD GetFrameName(nsAString& aResult) const;
 #endif
 
 protected:
   nsXULScrollFrame(nsIPresShell* aShell, nsStyleContext* aContext, PRBool aIsRoot);
   virtual PRIntn GetSkipSides() const;
 
+  void ClampAndSetBounds(nsBoxLayoutState& aState, 
+                         nsRect& aRect,
+                         nsPoint aScrollPosition,
+                         PRBool aRemoveOverflowAreas = PR_FALSE) {
+    /* 
+     * For RTL frames, restore the original scrolled position of the right
+     * edge, then subtract the current width to find the physical position.
+     * This can break the invariant that the scroll position is a multiple of
+     * device pixels, so round off the result to the nearest device pixel.
+     */
+    if (!mInner.IsLTR()) {
+      aRect.x = PresContext()->RoundAppUnitsToNearestDevPixels(
+         mInner.mScrollPort.XMost() - aScrollPosition.x - aRect.width);
+    }
+    mInner.mScrolledFrame->SetBounds(aState, aRect, aRemoveOverflowAreas);
+  }
+
 private:
   friend class nsGfxScrollFrameInner;
   nsGfxScrollFrameInner mInner;
 };
 
 #endif /* nsGfxScrollFrame_h___ */