Computer Locking Up During Gaming/Rendering

Okay, this is probably convoluted and problematic, so please forgive the long post.

Problem:
When I'm using my system, the following programs will lock up the PC:
City of Heroes/Villains
Poser 6

System Specs:
Inno3D GeForce 8600GT

Apevia/Aspire Beast680W PSU*
Soundblaster Audigy
2.00GB Crucial RAM
AMD Athlon 64x2 4200+ 2.20ghz
ASUS M2V Green
ATX Mid Tower case 2 fans
Windows Vista Ultimate SP1 (32-bit version)

*Recently replaced a 520W PSU with the 680, as there was an additional constant drop of my internet connection. As I thought there was too much power being drawn by the video card, I upped the PSU just in case.

Actions already taken:
In addition to the PSU change, I've done the following:
*Updated all drivers
*Reset BIOS

Insofar as I know, I'm not overclocking anything, nor do I think anything was factory OC'ed.

I'm tempted to think that it's time to get a new mobo, but I'd like a few more opinoins on this before I do. Thanks for any assistance.

 

So you're saying only those two things lock up your machine? Do any other graphic intensive programs run ok? I would take a look at the video card before you start eyeballing the motherboard..........

 

I play CoH as well. Try setting the "multi-display/mixed-gpu acceleration" to "single display performance mode". This is a known issue for the game with the new nvidia drivers which set it to multi display performance by default.

If that doesnt help than you should really post on the CoH forums in the technical questions section.

 

Okay, I did that and it fixed not only the COH problem, but the Poser problem as well. Odd, but I'm not going to complain (I don't have dual monitors). Thanks!

EDIT: okay, while it fixed the Poser problem, the COH one came right back. Guess I will have to report this to NCSoft. Thanks though.