It's been months and it's still at it after so many drivers
Games affected are Resident Evil 5 in DX10 and PCSX2 in DX10, seems like using any of them in DX9 makes the problem go away. IM popups simply appear and flicker over the image but everything remains fullscreen. It seems that anything DX10 does it. The graphics card brand is XFX 9600 GT.