I got the same bug when using 1.0-9631 on Ubuntu Edgy, which runs on a 2.6.17 kernel. So the bleeding edge kernel shouldn't be necessary to reproduce the problem.
The reason why only a few Ubuntu users have reported this problem might be because Ubuntu Edgy provides a packaged version of 1.0-8776, but no packaged version of 1.0-9xxx, so the number of people using Edgy + 1.0-9xxx would be reasonably low. Ubuntu Feisty does provide a packaged version of 1.0-9631, but it hasn't been released yet, so the number of people using Feisty + 1.0-9xxx would be reasonably low as well. Similiar reasons might apply to other distros. That only Ubuntu users report these problems is indeed suspicious, but it might simply be caused by Ubuntu's soaring popularity.
If the bug is indeed caused by a component of Ubuntu, then that component works fine with 1.0-8776, but doesn't work with 1.0-9631. While that is certainly possible, it seems more likely that the bug is in nVidia's sources. If you have any ideas about which component of Ubuntu is at fault, I will happily file a bug report for Ubuntu's devs to look into.
Lastly, please answer this question: Could you or another nVidia developer provide a patch for the 1.0-8776 driver that makes it compilable on Ubuntu Feisty? I've found a patch
from zander that supposedly makes 1.0-8776 buildable on 2.6.19 kernels, but that one didn't work for me.