Help! Everything's gone nuts!
 

Ok, I've got an '05 Sunfire with about 47,000 miles on it.

The other day when I got home from work I noticed the Theft System light was on, and I think the Service light. I shut the car off and started it again, and it had gone away. Didn't think much of it.

Last night I got in and started the car and when I put my foot on the brake it would not go out of Park. Shut it down and started it again and all was fine -- until I got home. When I took the key out of the ignition and got out of the car, my radio was still going and my daytime running lights were still on. I popped the hood and unhooked the battery to keep it from going dead over night.

This morning I hooked the battery back up and started the car. The radio will not turn on, and the instrument cluster is dead. The odometer is ok, but the speedo, tach, temp, and fuel gauges are don't register.

Any ideas on what could be causing this massive weirdness?