Comment 10 for bug 449196

Don't know if this helps hone in on the issue, but here are the symptoms on the box I have that's similarly affected:

- it happens when i have two gui sessions on say vt7 and vt8 logged in as different users
- as i switch back and forth between the two, the Xorg related to the vt that's *NOT* visible goes to 100%
- sometimes it takes a minute or two after a vt switch to go up to 100%.
- when it goes to 100%, it does it suddenly - it doesn't "ramp up"
- it only saturates one of the two cores at any given time, though it does switch back and forth between them over time.
- it does not seem to be related to a screensaver, since it happens in far less than the 15 minutes that's set to kick in at.
- if Ii switch to a text session - say vt1, the high cpu remains with the Xorg pid it was already saturating (i.e. the one *not* visible prior to the switch to vt1). it doesn't saturate the other one.

This is a new karmic beta install, though I also ave an lv with a system that I upgraded into karmic that I could still boot into. That behaved the same way - that behavior is what drove me to try doing a new install.

All fwiw - hope it helps. I'd be happy to supply any info about my system that might be needed/useful.