No haven't tried it with other ram. Have been getting random freezes (usually during video related functions) running PC on both Vista 64 (bought with) and now Windows 7(64). The RAM not being on the list concerned me and I wasn't sure if this could simply be the problem.
Try the RAM in another PC, or test your PC with another RAM. If you can see the same problem with another RAM installed on your PC, the problem could be the GPU.