Are you using Beryl or Compiz? I'm having a similar problem on my laptop and it only happens when I'm using both my wireless connection and Beryl together. If I'm only using one of the two, I have no problems. I'm using the proprietary Nvidia driver as well as a ndiswrapper setup for my Broadcom wireless card.
One other thing that I noticed set this off was in the Beryl installation, I switched the default screen depth from 16 to 24...may be coincidental because Beryl wouldn't run without it, but the lock-ups did not start for me until I had both Beryl and my wireless card running. -- hangups https://launchpad.net/bugs/59857 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
