diff --git a/gfx/src/gtk/nsDeviceContextGTK.cpp b/gfx/src/gtk/nsDeviceContextGTK.cpp
index c77ca4d43d31..b3a1a0ec3d14 100644
--- a/gfx/src/gtk/nsDeviceContextGTK.cpp
+++ b/gfx/src/gtk/nsDeviceContextGTK.cpp
@@ -51,6 +51,11 @@ nsDeviceContextGTK::nsDeviceContextGTK()
   mPaletteInfo.numReserved = 0;
   mPaletteInfo.palette = NULL;
   mNumCells = 0;
+
+  mWidthFloat = 0.0f;
+  mHeightFloat = 0.0f;
+  mWidth = -1;
+  mHeight = -1;
 }
 
 nsDeviceContextGTK::~nsDeviceContextGTK()
@@ -134,6 +139,9 @@ NS_IMETHODIMP nsDeviceContextGTK::Init(nsNativeWidget aNativeWidget)
   gtk_widget_destroy(sb);
   gtk_widget_unref(sb);
 
+  mWidthFloat = (float) gdk_screen_width();
+  mHeightFloat = (float) gdk_screen_height();
+
 #ifdef DEBUG
   static PRBool once = PR_TRUE;
   if (once) {
@@ -142,6 +150,8 @@ NS_IMETHODIMP nsDeviceContextGTK::Init(nsNativeWidget aNativeWidget)
   }
 #endif
 
+  DeviceContextImpl::CommonInit();
+
   return NS_OK;
 }
 
@@ -182,7 +192,7 @@ NS_IMETHODIMP nsDeviceContextGTK::CreateRenderingContext(nsIRenderingContext *&a
                                w->allocation.width,
                                w->allocation.height,
                                gdk_rgb_get_visual()->depth);
-        
+
         GdkGC *gc = gdk_gc_new(win);
 
         // init the nsDrawingSurfaceGTK
@@ -368,10 +378,16 @@ NS_IMETHODIMP nsDeviceContextGTK::CheckFontExistence(const nsString& aFontName)
 
 NS_IMETHODIMP nsDeviceContextGTK::GetDeviceSurfaceDimensions(PRInt32 &aWidth, PRInt32 &aHeight)
 {
-  aWidth = 1;
-  aHeight = 1;
+  if (mWidth == -1)
+    mWidth = NSToIntRound(mWidthFloat * mDevUnitsToAppUnits);
 
-  return NS_ERROR_FAILURE;
+  if (mHeight == -1)
+    mHeight = NSToIntRound(mHeightFloat * mDevUnitsToAppUnits);
+
+  aWidth = mWidth;
+  aHeight = mHeight;
+
+  return NS_OK;
 }
 
 NS_IMETHODIMP nsDeviceContextGTK::GetDeviceContextFor(nsIDeviceContextSpec *aDevice,
diff --git a/gfx/src/gtk/nsDeviceContextGTK.h b/gfx/src/gtk/nsDeviceContextGTK.h
index f20ee7ed2a27..6759631d96c5 100644
--- a/gfx/src/gtk/nsDeviceContextGTK.h
+++ b/gfx/src/gtk/nsDeviceContextGTK.h
@@ -70,9 +70,14 @@ private:
   PRUint32      mDepth;
   PRBool        mWriteable;
   nsPaletteInfo mPaletteInfo;
-  PRUint32 mNumCells;
-  PRInt16 mScrollbarHeight;
-  PRInt16 mScrollbarWidth;
+  PRUint32      mNumCells;
+  PRInt16       mScrollbarHeight;
+  PRInt16       mScrollbarWidth;
+
+  float         mWidthFloat;
+  float         mHeightFloat;
+  PRInt32       mWidth;
+  PRInt32       mHeight;
 };
 
 #endif /* nsDeviceContextGTK_h___ */
diff --git a/gfx/src/xlib/nsDeviceContextXlib.cpp b/gfx/src/xlib/nsDeviceContextXlib.cpp
index eced8e152b55..8a6718eb70f8 100644
--- a/gfx/src/xlib/nsDeviceContextXlib.cpp
+++ b/gfx/src/xlib/nsDeviceContextXlib.cpp
@@ -52,6 +52,11 @@ nsDeviceContextXlib::nsDeviceContextXlib()
   mScreen = nsnull;
   mVisual = nsnull;
   mDepth = 0;
+
+  mWidthFloat = 0.0f;
+  mHeightFloat = 0.0f;
+  mWidth = -1;
+  mHeight = -1;
 }
 
 nsDeviceContextXlib::~nsDeviceContextXlib()
@@ -127,6 +132,10 @@ nsDeviceContextXlib::CommonInit(void)
 
   PR_LOG(DeviceContextXlibLM, PR_LOG_DEBUG, ("GFX: dpi=%d t2p=%g p2t=%g\n", dpi, mTwipsToPixels, mPixelsToTwips));
 
+
+  mWidthFloat = (float) WidthOfScreen(mScreen);
+  mHeightFloat = (float) HeightOfScreen(mScreen);
+
   DeviceContextImpl::CommonInit();
 }
 
@@ -344,9 +353,15 @@ NS_IMETHODIMP nsDeviceContextXlib::CheckFontExistence(const nsString& aFontName)
 
 NS_IMETHODIMP nsDeviceContextXlib::GetDeviceSurfaceDimensions(PRInt32 &aWidth, PRInt32 &aHeight)
 {
-  PR_LOG(DeviceContextXlibLM, PR_LOG_DEBUG, ("nsDeviceContextXlib::GetDeviceSurfaceDimensions()\n"));
-  aWidth = 1;
-  aHeight = 1;
+  if (mWidth == -1)
+    mWidth = NSToIntRound(mWidthFloat * mDevUnitsToAppUnits);
+
+  if (mHeight == -1)
+    mHeight = NSToIntRound(mHeightFloat * mDevUnitsToAppUnits);
+
+  aWidth = mWidth;
+  aHeight = mHeight;
+
   return NS_OK;
 }
 
diff --git a/gfx/src/xlib/nsDeviceContextXlib.h b/gfx/src/xlib/nsDeviceContextXlib.h
index 4fedfdc8f5fe..488182d2643b 100644
--- a/gfx/src/xlib/nsDeviceContextXlib.h
+++ b/gfx/src/xlib/nsDeviceContextXlib.h
@@ -71,6 +71,11 @@ private:
   Screen *             mScreen;
   Visual *             mVisual;
   int                  mDepth;
+
+  float                mWidthFloat;
+  float                mHeightFloat;
+  PRInt32              mWidth;
+  PRInt32              mHeight;
 };
 
 #endif