I've tried several things.

I've logged in as root and did an "apt-get update" and everything updated fine (there were some GPG errors, but according to a message here that wasn't really a problem). No change.

The only recent change was virtual memory. So I disabled that. Nothing.

I've removed all SD cards and the battery. Waited. Put just the battery back in and started it back up. Nothing.

Everything else seems to work just fine.