I purchased and downloaded a lesser-known FPS from Gamersgate called You are Empty (released in 2006). It seems to run fine on Windows 7 64 bit, apart from one problem: picking up a healing item or taking damage is supposed to flash a blue or red transparent layer over the screen momentarily. At least according to gameplay videos I've seen. However, in my version, the layer is opaque rather than transparent, which makes the game nearly unplayable.

I expect this is a DX issue, but I don't have any clue how to solve it. Does anyone have any suggestions?