The Kernal panics happen totally randomly when using different software, (iTunes, Safari, Mail, QuickTime, Word, Excel, BBedit, etc). I have a PowerBook G4 800Mhz 1GB of RAM (2 Dimms. Installed by Apple when I purchased the Laptop). I am using Mac OS X 10.4.1 I dont have any external hardware connected to the laptop. I dont have any firewalls running. I havent installed any extra fonts on the system. There are no applications running in the background. All software and firmware are up to date. Heres what I have tried so far: Repair permissions (using Terminal). Check for any disk errors (using fsck f and again using install CD). Zapped RAM (using alt+option+p+r on startup). Run a system maintenance application (Updating Prebinding, clearing cache, etc). 2 clean installs of Tiger. Removing the RAM and installing it again. Run Hardware Diagnostic CD that came with my PowerBook. I would be very grateful if someone has any other suggestions I could try?