OK, I think figured it out.

Removed the extra power cord from my GF 9600GT, so it would run 'half speed', it fixed the problem, and now everything's working smoothly.

The problem must be my underpowered PSU, guess the only thing a 430W is good for nowadays is a HTPC with an integrated 3D card.

So what I did was order a new 850W Nexus RX-8500 <15.5dB modular PSU

Thanks for the input and happy hacking guys!