diff --git a/mozilla/docshell/base/nsDocShell.cpp b/mozilla/docshell/base/nsDocShell.cpp
index a8d1ceb0a5e..cb0d16d1ca1 100644
--- a/mozilla/docshell/base/nsDocShell.cpp
+++ b/mozilla/docshell/base/nsDocShell.cpp
@@ -5433,9 +5433,12 @@ nsDocShell::RestoreFromHistory()
 
     nsCOMPtr<nsIMarkupDocumentViewer> oldMUDV(do_QueryInterface(mContentViewer));
     nsCOMPtr<nsIMarkupDocumentViewer> newMUDV(do_QueryInterface(viewer));
-    float zoom = 1.0;
-    if (oldMUDV && newMUDV)
-        oldMUDV->GetTextZoom(&zoom);
+    float textZoom = 1.0f;
+    float pageZoom = 1.0f;
+    if (oldMUDV && newMUDV) {
+        oldMUDV->GetTextZoom(&textZoom);
+        oldMUDV->GetFullZoom(&pageZoom);
+    }
 
     // Protect against mLSHE going away via a load triggered from
     // pagehide or unload.
@@ -5614,8 +5617,10 @@ nsDocShell::RestoreFromHistory()
         FavorPerformanceHint(PR_TRUE, NS_EVENT_STARVATION_DELAY_HINT);
 
 
-    if (oldMUDV && newMUDV)
-        newMUDV->SetTextZoom(zoom);
+    if (oldMUDV && newMUDV) {
+        newMUDV->SetTextZoom(textZoom);
+        newMUDV->SetFullZoom(pageZoom);
+    }
 
     nsCOMPtr<nsIDocument> document = do_QueryInterface(domDoc);
     if (document) {
@@ -5947,6 +5952,7 @@ nsDocShell::SetupNewViewer(nsIContentViewer * aNewViewer)
     PRInt32 hintCharsetSource;
     nsCAutoString prevDocCharset;
     float textZoom;
+    float pageZoom;
     PRBool styleDisabled;
     // |newMUDV| also serves as a flag to set the data from the above vars
     nsCOMPtr<nsIMarkupDocumentViewer> newMUDV;
@@ -5996,6 +6002,9 @@ nsDocShell::SetupNewViewer(nsIContentViewer * aNewViewer)
                 NS_ENSURE_SUCCESS(oldMUDV->
                                   GetTextZoom(&textZoom),
                                   NS_ERROR_FAILURE);
+                NS_ENSURE_SUCCESS(oldMUDV->
+                                  GetFullZoom(&pageZoom),
+                                  NS_ERROR_FAILURE);
                 NS_ENSURE_SUCCESS(oldMUDV->
                                   GetAuthorStyleDisabled(&styleDisabled),
                                   NS_ERROR_FAILURE);
@@ -6130,6 +6139,8 @@ nsDocShell::SetupNewViewer(nsIContentViewer * aNewViewer)
                           NS_ERROR_FAILURE);
         NS_ENSURE_SUCCESS(newMUDV->SetTextZoom(textZoom),
                           NS_ERROR_FAILURE);
+        NS_ENSURE_SUCCESS(newMUDV->SetFullZoom(pageZoom),
+                          NS_ERROR_FAILURE);
         NS_ENSURE_SUCCESS(newMUDV->SetAuthorStyleDisabled(styleDisabled),
                           NS_ERROR_FAILURE);
     }
diff --git a/mozilla/layout/base/nsDocumentViewer.cpp b/mozilla/layout/base/nsDocumentViewer.cpp
index 5904f02915d..4ca42f4ac65 100644
--- a/mozilla/layout/base/nsDocumentViewer.cpp
+++ b/mozilla/layout/base/nsDocumentViewer.cpp
@@ -412,6 +412,7 @@ protected:
   nsIWidget* mParentWidget;          // purposely won't be ref counted
 
   float mTextZoom;      // Text zoom, defaults to 1.0
+  float mPageZoom;
 
   PRInt16 mNumURLStarts;
   PRInt16 mDestroyRefCount;    // a second "refcount" for the document viewer's "destroy"
@@ -507,7 +508,7 @@ void DocumentViewerImpl::PrepareToStartLoad()
 
 // Note: operator new zeros our memory, so no need to init things to null.
 DocumentViewerImpl::DocumentViewerImpl()
-  : mTextZoom(1.0),
+  : mTextZoom(1.0), mPageZoom(1.0),
     mIsSticky(PR_TRUE),
     mHintCharsetSource(kCharsetUninitialized)
 {
@@ -682,12 +683,13 @@ DocumentViewerImpl::InitPresentationStuff(PRBool aDoInitialReflow)
   nsRect bounds;
   mWindow->GetBounds(bounds);
 
-  nscoord width = mPresContext->DevPixelsToAppUnits(bounds.width);
-  nscoord height = mPresContext->DevPixelsToAppUnits(bounds.height);
+  nscoord width = mPresContext->DeviceContext()->UnscaledAppUnitsPerDevPixel() * bounds.width;
+  nscoord height = mPresContext->DeviceContext()->UnscaledAppUnitsPerDevPixel() * bounds.height;
 
   mViewManager->DisableRefresh();
   mViewManager->SetWindowDimensions(width, height);
   mPresContext->SetTextZoom(mTextZoom);
+  mPresContext->SetFullZoom(mPageZoom);
 
   // Setup default view manager background color
 
@@ -2716,6 +2718,7 @@ DocumentViewerImpl::GetTextZoom(float* aTextZoom)
 NS_IMETHODIMP
 DocumentViewerImpl::SetFullZoom(float aFullZoom)
 {
+  mPageZoom = aFullZoom;
   struct ZoomInfo ZoomInfo = { aFullZoom };
   CallChildren(SetChildFullZoom, &ZoomInfo);
   if (mPresContext) {
@@ -2729,7 +2732,9 @@ NS_IMETHODIMP
 DocumentViewerImpl::GetFullZoom(float* aFullZoom)
 {
   NS_ENSURE_ARG_POINTER(aFullZoom);
-  *aFullZoom = mPresContext ? mPresContext->GetFullZoom() : 1.0;
+  NS_ASSERTION(!mPresContext || mPresContext->GetFullZoom() == mPageZoom, 
+               "mPresContext->GetFullZoom() != mPageZoom");
+  *aFullZoom = mPresContext ? mPresContext->GetFullZoom() : 1.0f;
   return NS_OK;
 }