If it's a VIA chipset on the Athlon motherboard, try loading the latest VIA 4 in 1 Driver package. This seems to stabilize 90% of crashing Athlon systems than I encounter. The video card has virtually nothing to do with Poser. Poser does all of its 3D work internally, through a software renderer. It uses the video card simply as a 2D display, to show a bitmapped image when the render is done. So it shouldn't care at all about the video card. So statements like "Poser4 just can't handle the new power" are just plain wrong. On the other hand, Poser does a lot of floating point math, and wide ranging memory accesses, so it does really stress test a somputer system, revealing instabilities that a lighter workload won't find. And some hardware combinations are notoriously unstable in such use, including certain combinations of VIA chipsets, nVidia cards, and Athlon processors. Especially video cards that take over the processor bus when they shouldn't, corrupting data transfer from CPU to RAM. usually, upgrading to the latest chipset drivers and video card drivers clears these things up.