Fullscreen at non-native resolution not working

Setting fullscreen state (DXGI_SWAP_CHAIN_DESC.Windowed = 0) with a resolution lower than native will result in the image being centered on screen but not filling out the whole monitor (windowboxed image). I’ve also set DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH when creating the swap chain, or calling ResizeBuffers, and have confirmed that it’s still set by calling GetDesc after creation and resizing. Testing with a debug device gave me an error saying that the chosen mode wasn’t in display mode list, fixed that by calling “FindClosestMatchingMode”. But still didn’t fix the issue. Now i get the following warning when resizing buffers:

DXGI WARNING: IDXGISwapChain::Present: Fullscreen presentation inefficiencies incurred due to application not using IDXGISwapChain::ResizeBuffers appropriately, specifying a DXGI_MODE_DESC not available in IDXGIOutput::GetDisplayModeList, or not using DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH.DXGI_SWAP_CHAIN_DESC::BufferDesc = { 1280, 768, { 60000, 1000 }, R8G8B8A8_UNORM_SRGB, 1, 0 }; DXGI_SWAP_CHAIN_DESC::SampleDesc = { 1, 0 }; DXGI_SWAP_CHAIN_DESC::Flags = 0x2; [ MISCELLANEOUS WARNING #98: ]

I am using a mode in the display mode list and DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH is set (see the flags parameters). I’ve also tried with Driver versions 334.89 and 337.88.

Originally I thought that this was a problem in my code, but now I’m experiencing it in other comercial games. I launched Dragon Age Origins and was seeing the issue, and I launched Borderlands 2 and was also seeing the issue.

Also, the screen resolution does change, as i can see the windows move on my secondary monitor. In other words, windows that were maximized and set to 1920x1200 will bleed over to the secondary monitor when dropping to 1280x720 in the fullscreen game, which is a behavior I’m familiar with and seen happen many times. The screen is changing to 1280x720, seeing windows run behind it is shurnk as well. Start menu is in the bottom left of the image, ie the image is my whole desktop not a window crop as if it weren’t resized.

I’m running windows 7 pro.