15" MBP Penryn, 2.5ghz, 250gb 5400rpm drive, 4gb ram. Trying to switch from my main account to one of the other user accounts. The account starts to load, the menu bar comes up, then the hard drive icon starts slowly blinking. The menu bar disappears with it unless I open a program from the dock. Can't open a finder window. Even with another program open, when the hard drive icon shows back up, the non-existent finder window steals focus until it disappears again. Only way I can get out is to hit the power button, click restart, then click switch user. Tried rebooting and repaired permissions. Still does it. That's pretty much the end of my Mac trouble shooting skills. If I switch to either of the other two user accounts, they load just fine. The last time I tried switching to the problem account, the fans ramped up loudly. In the few seconds it took to switch back to the main account iStat said the CPU was 85 degrees and the fans were 6700 rpm. I usually run 65/2000 (which I understand is a tad high anyways, but that's another subject.) So, what's wrong and how do I fix it?