If you submit a Ticket on this please include the Poser log window. If the GPU grays out there should be an error in the log. Also once a render fails in GPU it needs to be reset and right now the only way is to exit Poser and Relaunch Poser. So launch Poser, render the offending scene and copy the text out of the log window. That will help us find if it's a bug in Cuda or the scene was just too big to fit on GPU memory.