Still need HELP!

[clinthawkins]

Version: 2008
Operating System: Mac OS X 10.5 (Leopard)
Processor: Intel

New Quad core Mac pro, new office install, dual NVIDIA Geforce GT 120's (in the 16x slots) running two identical 24 inch screens w 6 gigs of memory.
Goes into presenter mode and within a few slides, hangs the machine & it will accept a mouse click about every 30 seconds. Powerpoint is the only thing that triggers this, and once it triggers, it's unstable until a restart (even if I can get out of PPT). Thought it was a bad vid card, reseated it, all good, but it's COMPLETELY stable with everything until PPT trips it up.
Any thoughts?

Single monitor mode has no problems at all, I've even mirrored them and turned one off so I can get some work done.

 

[clinthawkins]

I even swapped main & secondary momnitor designations... infinitely worse, screen displays all sorts of artifacts & random pixelly garbage. Everything else on this machine is just fine (graphic intensive apps, renders, video editing, everything). It ONLY trips on Powerpoint presenter mode after about 5-10 clicks/advances. What's up?

In single monitor mode everythings smooth and fully functional.