Help! Green Flickering then crash while play some games.

Recently I've searched around for some old post-apocalypse games and downloaded two. STALKER: Call of Pripyat (Which is know to have a bunch of problems and is playable if I ONLY keep it in windowed and with dirextX shading off-Static Lighting) and Metro 2033( Which starts up for a bit flashing green lines then crashes)

As well now as some other games do this. Some of them are playable but the green lines flicker and flow. Ive never had this problem before.

my system is easily able to play games such as BF3 and Skyrim on max

AMD Radeon HD 6700 Seriesx2 Crossfired
Processor AMD A8-3870 APU with Radeon(tm) HD Graphics, 3000 Mhz, 4 Core(s), 4 Logical Processor(s)
RAM 16G

Again this has never happened to just recently, Ive had no virus or problems with my PC until now. I would really appreciate the help and look forward to hearing from you.

*Edit* My AMD catalyst wont update from 12.3 to 12.4 even if I install it. Also I can mess with the settings. For instance manual fan control, if I set it higher it wont do anything they just stay on auto. Going to roll back to 12.1 see how that works.

*Edit#2* Ok the catalyst update seems to be a prob with everyone so im not to worried about that. However when I disable Crossfire the green flickering is gone.... why is this?