New Video problem

[MasterCraft]

New video problem, got it back together, started benching, then started playing a game, then game locked up. Now no video using two different cards. Any ideas why?

[MasterCraft]

update - due to the brief reply

I did a nvidia detect optimum settings on the VGA, gave me 447/1190

I started benching in aquamark, which gave me 71k.

after about 3 hours of running and good temps (I just installed watercooling)

I started playing a game, about 30 minutes into it, the came locks up, my sound goes nuts, and eventually i hit the power and restart.

I restarted to no video, natta.

now it's working, but for how long? I need to figure out what the deal is so that it doesn't happen again, any ideas?