Description of problem:
After a few seconds of inactivity (no mouse or keyboard usage), the system freezes. Cursors stop blinking, the System Monitor stops updating, and videos start replaying in a short loop, like a buffer is constantly replayed. If I move the mouse or type on the keyboard, the system unfreezes again.

Version-Release number of selected component (if applicable):
This is on Nouveau Testing Day for Fedora 15

How reproducible:
Always

Steps to Reproduce:
1. Boot nouveau testing day image with default options.
2. Open a terminal.
3. Wait a few seconds.
  
Actual results:
The cursor stops blinking.

Expected results:
The cursor keeps blinking.

Additional info:
A workaround exists: if you put in nolapic_timer as a boot option, the system doesn't freeze anymore.

It also happens on Ubuntu: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/643822