keyboard failure

Hi, Since a few days I regularly have troubles with my keyboard under Trinity: it doesn't work anymore after some time, except for a few combinations like ctrl-alt-suppr, ctrl-alt-f1, and the leds are still responding (num & caps lock, etc.) but *I cannot type texte anymore*. I can still switch to tty1 and use my keyboard normally in there. Since the mouse is responding normally under X, I can also launch a new X session (via the "T menu") and experience that the keyboard is working well on the kdm-trinity login screen. So this really looks like a Trinity issue or, at least, a Trinity x-session related issue. I use Debian squeeze and Trinity on a laptop and an usb keyboard. Note that: - the laptop sometimes has heat problems and the "X screen" gone crazy, I think becasue the video chip is too hot (often the case on laptops... and that's a shame). But, I'll be surprised if this keyboard issue is linked to hardware issue because the keyboard is working everywhere else, - the behavior is exactly the same on the laptop's built-in keyboard, - plugging out/in the keayboard has no effect, - plugging in another keayboard has no effect. I don't know what to do with that. I found nothing related in the main log files. Maybe this is a race hardware issue... Any advice or tracing tricks would be appreciated. Thank you for reading. Nicolas