Comment 17 for bug 103400

Reproduced this issue with linux-restricted-modules-2.6.28-14-generic on up-to-date Jaunty (with 8600gts, 8 gigs amd64).

System didn't seem to respond to keyboard input besides num/caps-lock, but I could switch to another user account with mouse.
Workaround: Switching away from the session and then back to the user account with the problem (and thus re-unlocking screensaver) seems to fix the symptoms.

Looks like a race condition - seen only once with this computer so far, and not with Hardy/Intrepid.