Steam: Black Screening

[pottypie]

I appear to be having some trouble making anything work.

The main menu and loading screens work fine, but anywhere else, the screen is totally black. This includes the starting titles, and all the game maps (excluding the minimap, strangely). From what I can gather, this problem was big around a year ago, and was supposed to have been fixed. I followed the advice anyway, and no result. I have tried deleting local content on both games and reinstalling them, and no change.

Any help?