Mike, my first guess would be old drivers that don't have the right SDK package or no Open CL support. If it's and ATI GPU, then Moo! and especially Collatz should run on it. The only problem I can think of is if it doesn't have enough video RAM to crunch. You can check that possibility by going into the Event Log in BOINC, and seeing if it's disabling the GPU or whatever it's saying after it searches for what GPU is installed. It will be close to the top of the log when you first start up BOINC and next to where it lists your CPU specs.