Originally posted by trypma
I also had kernel panics immediately after upgrading to 10.2.5 using Software Update. I could at most get 5 minutes of operation before failure, and a required power-off and reboot. Since the kernel panic message mentioned USBHub in the software stack, I thought I'd disconnect my extra USB (2.0) hub with iMic, printer, UPS and Palm connector. The system then kept running long enough for me to download the OS X 10.2.5 Combo updater and re-install 10.2.5 from this.
So far, the system is stable, with USB hub unconnected, but it still fails within 5 minutes when the hub is re-connected. Now I need to wait for a fix or downgrade, painfully I suspect.