The crashes on NV cards are from a line of code I forgot to remove while fixing the earlier ATI problem. This has been fixed. My apologies for any frustration this has caused.
@kehziah: Yes, the executable was a little large. I made some changes and reduced it to around 268K. As for the dlls, I haven't figured out how to statically link to the Cg runtime. I know it was possible with the beta version of the Cg libraries, but I haven't had much time to learn how to do it now. Does any one else know?
Also, the demo uses ARB FP1 and VP1 for per-pixel lighting. IIRC the 8500 supports only the ATI fragment shader extension. I may add support for PPL on a broader range of hardware in the future, but using ARB FP/VP was a time vs. necessity choice--this is a demonstration of transparent windows, after all.
I've only had a few complaints since I broke the demo for NV hardware. The implications of that are interesting.
Thanks again for the responses,