MCP7x IGP/gt200 combo - any experience?

We are in the process of building a GPU cluster and our testbed platform is an ECS GF8200A AMD motherboard, an AMD Phenom 9350e 65w CPU and an MSI GTX 275. After installing Fedora 10 64-bit and Cuda 2.2, I found that running any of the SDK applications would lock the machine. Pulling the GTX 275 “fixed” the problem, although this was hardly satisfactory. Neither installing Cuda 2.3, nor systematic experimentation with the BIOS settings regarding the IGP made any difference. All SDK applications completely lock the machine immediately after performing a device query. Previous tests with this same environment using an AMD 790 (non-CUDA) chipset ran without incident. Is anyone else using a GT200 card on a motherboard equipped with a CUDA-capable internal GPU?