Keyboard response

Dear list, I have a random problem with the keyboard response. Once ina while it starts crashing and does not respond anymore. Then I have to logout and login (which means basically to restart the X-server, right?) andit works again. I cannot figure out to what it is related. It could be related to the following programs: Lyx, Xscreensaver, Xfree86. It is not related to acpi or a dirty keyboard. I am running SuSE 9.0 on a DELL Inspiron 8200. But it also happend under 8.2. It might be the X-serve which is not running stable. Any help apreciated. Ulrich