KlemenBr :
Hi, I had the same problem as you. I have HP EliteBook Workstation 8560w. Go to ControlPanel->PerformanceInformationAndTools->AdvancedTools->ViewPerformanceDetailsIn EventLog ... Choose EventViewer (Local) on the top of the tree and check for errors and warnings. Your problem causes the source with most errors/warnings in the column of last hour. I have 2000 warnings from same source and it was problem of HP Software Framework. I deleted the HP Power Assistant and everithing started working normal.
OMG! Dude, you just saved my life, really. I was looking for this ******* freezing problem for about 5 hours, I was almost freaking out here, and just about to go to sleep when you showed up talking about the HP Power Assistant. I really dunno whatahell happened, it wasnt giving me trouble before but maybe some automatic update happened and the HP Power Assistant was indeed the root of my problem. I can't express my thankfull for your comment, I was really considering taking my laptop to a technician, but you showed up and now I can sleep happy.
One question: are you brazilian?