On 10.3.1 and 10.3.2, I had this happen frequently on my iBook (600MHz G3).
The solution that worked for me was to run Panther Cache Cleaner & delete all caches (deep cleaning), reboot and repair permissions, then reboot from the DiskWarrior CD and rebuild the the directories.
Since these steps, I haven't had any KPs upon waking. YMMV.
And it also seems to have survived the update to 10.3.3.