Thank you for all your feedback on this matter.
Just be aware that the issue was identified and a fix has not been implemented yet.
Some users claim that the win8.1 beta driver that was released, alleviates the issue, which is nice to know, however keep in mind this beta driver was not released for the purpose of solving the corruption issue on XBMC. I still forward the feedback you provide on that driver even though it is not for this purpose, for example the VC1 playback issue mentioned by mcfaul.