MC 8.4 Playback issue

Hi,

I have a playback issue on Media Composer 8.4. When I hit play on the timeline randomly the cursor stops or jump to the beginning of the timeline.

I have installed the cuda driver for mac and Quick time Pro7.

Everything else seems to work fine. The Video Format in Avid is the same as the reels. 

I don't know if it's an hardware issue or a software.

My infos:Hackintosh

OSX 10.9.5

CPU: i7 4970K

RAM:16 Go

GPU: GT 640 1 Go

Any idea? 

Thanks