Trash comes from keyboard when returns from hibernation

[doodles113]

Hello,

I'm having a very weird problem:Sometimes when my machine come back from hibernation, some strange characters is displayed instead of my password. do you guys have any idea on how to solve this?
My Win Xp has been re-installed from scratch,on a 40GB drive(a gift from a friend who have the laptop stolen...)and all os patches and SP2 has been applied, w/o success.Also updated the BIOS to 1IET69WW(version 2.08)and embedded controller to 1IHT18WW (version 1.05)
Thanks in advance for any help,
Eduardo
ThinkPad T30,2366-85U,512mb mem,2x 40Gb Hdd, running WinXP or Linux