[BUG] Black screen when Windowed

I select windowed and hit apply, it switched to windowed mode but the game was black. When restarted it was working fine but was back in fullscreen.

happens in 0.40.04
Version: Direct3D 9.0c [nvumdshim.dll]
Renderer: NVIDIA GeForce GTX 460 SE
Vendor: NVIDIA
VRAM: 978 MB (via DXGI)