Using maya 2014 64bit with windows 7 and a hd 6950 with no issues. Your problem might be a bad installation of windows 8. I am not sure if windows 8 has comparability mode like windows 7 and vista but if it does try setting it to windows 7 and run it.
Well ok, just for the records: formatted & installed win 7 just in case. After installing Maya guess what? exact same error, so must be something else... :S
I might consider turning back to windows 7 this weekend, tried reinstalling both, maya & nvidia drivers, and still stuck... crap! didnt even have time to test marmoset on this span! Anyways, I'm open to ideas until Friday. Thanks guys!