This morning I had two kernel panics while my MacBook Pro was sitting idle. In both cases it was caused by backupd (Time Machine). I had it set to back up wirelessly to a drive attached to my Mac Mini, but I shut time machine off for now. I also back up my home directory to my server automatically every night using rsync and back up the entire drive manually using SuperDuper to an external drive, so I don’t depend on Time Machine for my backups.