I had the same problem with my aveo a few months ago. I actually called my dealership and had it towed over there cause my shift lock release didn't even work. I asked the guy what the problem was and he said that there was a batch of shifters that had bad wiring that were installed on both the aveo and the cobalt. It is covered by the warranty so I would take it down and have them replace the entire shifter.

Another thing to ask about is that there was a recall on certain VIN numbers for the aveo regarding the fuel line. Apparently, and this is according to the dealership also, if your aveo falls in that VIN, when you get in an accident, the fuel pump doesn't shut off and keeps pumping fuel into the engine. In other words, you become a CRISPY KRITTER!!!!