--- a/gfx/layers/d3d10/LayerManagerD3D10.cpp
+++ b/gfx/layers/d3d10/LayerManagerD3D10.cpp
@@ -82,16 +82,22 @@ LayerManagerD3D10::LayerManagerD3D10(nsI
 {
 }
 
 LayerManagerD3D10::~LayerManagerD3D10()
 {
   Destroy();
 }
 
+static bool
+IsOptimus()
+{
+  return GetModuleHandleA("nvumdshim.dll");
+}
+
 bool
 LayerManagerD3D10::Initialize()
 {
   HRESULT hr;
 
   mDevice = gfxWindowsPlatform::GetPlatform()->GetD3D10Device();
   if (!mDevice) {
       return false;
@@ -177,18 +183,25 @@ LayerManagerD3D10::Initialize()
   swapDesc.BufferDesc.RefreshRate.Numerator = 60;
   swapDesc.BufferDesc.RefreshRate.Denominator = 1;
   swapDesc.SampleDesc.Count = 1;
   swapDesc.SampleDesc.Quality = 0;
   swapDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
   swapDesc.BufferCount = 1;
   // We don't really need this flag, however it seems on some NVidia hardware
   // smaller area windows do not present properly without this flag. This flag
-  // should have no negative consequences by itself. See bug 613790.
-  swapDesc.Flags = DXGI_SWAP_CHAIN_FLAG_GDI_COMPATIBLE;
+  // should have no negative consequences by itself. See bug 613790. This flag
+  // is broken on optimus devices. As a temporary solution we don't set it
+  // there, the only way of reliably detecting we're on optimus is looking for
+  // the DLL. See Bug 623807.
+  if (IsOptimus()) {
+    swapDesc.Flags = 0;
+  } else {
+    swapDesc.Flags = DXGI_SWAP_CHAIN_FLAG_GDI_COMPATIBLE;
+  }
   swapDesc.OutputWindow = (HWND)mWidget->GetNativeData(NS_NATIVE_WINDOW);
   swapDesc.Windowed = TRUE;
 
   /**
    * Create a swap chain, this swap chain will contain the backbuffer for
    * the window we draw to. The front buffer is the full screen front
    * buffer.
    */
@@ -429,19 +442,25 @@ LayerManagerD3D10::VerifyBufferSize()
   mWidget->GetClientBounds(rect);
 
   if (swapDesc.BufferDesc.Width == rect.width &&
       swapDesc.BufferDesc.Height == rect.height) {
     return;
   }
 
   mRTView = nsnull;
-  mSwapChain->ResizeBuffers(1, rect.width, rect.height,
-                            DXGI_FORMAT_B8G8R8A8_UNORM,
-                            DXGI_SWAP_CHAIN_FLAG_GDI_COMPATIBLE);
+  if (IsOptimus()) {
+    mSwapChain->ResizeBuffers(1, rect.width, rect.height,
+                              DXGI_FORMAT_B8G8R8A8_UNORM,
+                              0);
+  } else {
+    mSwapChain->ResizeBuffers(1, rect.width, rect.height,
+                              DXGI_FORMAT_B8G8R8A8_UNORM,
+                              DXGI_SWAP_CHAIN_FLAG_GDI_COMPATIBLE);
+  }
 
 }
 
 void
 LayerManagerD3D10::Render()
 {
   if (mRoot) {
     static_cast<LayerD3D10*>(mRoot->ImplData())->Validate();