VAC detected for modifying games, you CAN however use directdraw to overlay onto the game(which doesn't show on screenshots either).
The problem is that DirectDraw is decrapitated and is replaced by Direct2D(on win7/vista I believe).
And it uses some fancy color format called YUV on nvidia cards, making colors look all gay and shit if you use RGB(for ATI)
I'm willing to work on a directdraw version if thats what you guys want.