[SLE] opensuse 10.1 runs out of memory, then kernel panic

Hello, I've installed opensuse 10.1 (amd64) on a new system and it hangs after a few hours of being up. The hardware is dual Opteron with 4 gigs of ram. After booting the system there are no applications running but my available memory (given by top) eventually goes from 4 gigs down to zero, giving this message on the console: "Kernel panic - not syncing: Out of memory and no killable processes...". I'm running kernel version 2.6.16.13-4-smp and have also tried 2.6.16-20-smp with the same results. Does anyone know what could be causing this problem? thanks, Kevin