I decided to give a factorial prime sieve a try... runs great on the X86 version, but when I run either the 32 or 64 bit versions of the gpu cl app I get a virus warning. I didn't know if it was a false postive or not so I haven't added it to the exclusions. It detects W32/Exploit.gen.
If it's safe, I will certainly give it another shot. The .gen probably indicates a generic exploit and is probably ok, but I wanted to double check.