--- a/gfx/ipc/SharedDIBSurface.cpp
+++ b/gfx/ipc/SharedDIBSurface.cpp
@@ -69,21 +69,18 @@ SharedDIBSurface::Attach(Handle aHandle,
   InitSurface(aWidth, aHeight, aTransparent);
   return true;
 }
 
 void
 SharedDIBSurface::InitSurface(PRUint32 aWidth, PRUint32 aHeight,
                               bool aTransparent)
 {
-  // Windows DIBs are bottom-to-top by default, so the stride is negative
-  // and the data is the beginning of the last row.
-  long stride = -long(aWidth * kBytesPerPixel);
+  long stride = long(aWidth * kBytesPerPixel);
   unsigned char* data = reinterpret_cast<unsigned char*>(mSharedDIB.GetBits());
-  data -= (aHeight - 1) * stride;
 
   gfxImageFormat format = aTransparent ? ImageFormatARGB32 : ImageFormatRGB24;
 
   gfxImageSurface::InitWithData(data, gfxIntSize(aWidth, aHeight),
                                 stride, format);
 
   cairo_surface_set_user_data(mSurface, &SHAREDDIB_KEY, this, NULL);
 }

--- a/gfx/ipc/SharedDIBWin.cpp
+++ b/gfx/ipc/SharedDIBWin.cpp
@@ -119,31 +119,33 @@ SharedDIBWin::Attach(Handle aHandle, PRU
 
   return NS_OK;
 }
 
 PRUint32
 SharedDIBWin::SetupBitmapHeader(PRUint32 aWidth, PRUint32 aHeight,
                                 bool aTransparent, BITMAPV4HEADER *aHeader)
 {
+  // D3D cannot handle an offscreen memory that pitch (SysMemPitch) is negative.
+  // So we create top-to-bottom DIB.
   memset((void*)aHeader, 0, sizeof(BITMAPV4HEADER));
   aHeader->bV4Size          = sizeof(BITMAPV4HEADER);
   aHeader->bV4Width         = aWidth;
-  aHeader->bV4Height        = aHeight;
+  aHeader->bV4Height        = -LONG(aHeight); // top-to-buttom DIB
   aHeader->bV4Planes        = 1;
   aHeader->bV4BitCount      = 32;
   aHeader->bV4V4Compression = BI_BITFIELDS;
   aHeader->bV4RedMask       = 0x00FF0000;
   aHeader->bV4GreenMask     = 0x0000FF00;
   aHeader->bV4BlueMask      = 0x000000FF;
 
   if (aTransparent)
     aHeader->bV4AlphaMask     = 0xFF000000;
 
-  return (sizeof(BITMAPV4HEADER) + (aHeader->bV4Height * aHeader->bV4Width * kBytesPerPixel));
+  return (sizeof(BITMAPV4HEADER) + (-aHeader->bV4Height * aHeader->bV4Width * kBytesPerPixel));
 }
 
 nsresult
 SharedDIBWin::SetupSurface(HDC aHdc, BITMAPV4HEADER *aHdr)
 {
   mSharedHdc = ::CreateCompatibleDC(aHdc);
 
   if (!mSharedHdc)