Comment 11 for bug 332716

Comparing Xorg.0.logs from a working session (e.g. intrepid) with one from the current broken case might show something of use.

xtrace output to see what's getting communicated between server and client could be of use too. This could help show whether the xserver is delivering keyboard hit data or not. If it's delivering output to the client, then we know for certain the bug's in the client; otherwise, the bug is at a lower level (xserver, kernel, whatever.)

Since Hardy there's been a huge amount of change in the input subsystem of X. A lot of code and functionality has moved out of keyboard drivers and X, into the kernel via the 'evdev' module, and HAL is used to manage, coordinate, and configure it. This has been a pretty massive change, and a LOT of the recent keyboard/mouse regressions we've seen in the last two releases have been due to some aspect of this change. While this bug doesn't fit the normal symptoms of hal/evdev bugs, it is worth a mention. You could try forcing X to use the old non-hal/non-evdev keyboard/mouse handling and see if the issue goes away; if it does, that proves it's a bug in this new subsystem.