weird problem.... passlock????

my mom has a '00 malibu, and im having a really weird problem with it. sometimes when you put the key in the ignition, and go to start the car, the only thing that happens is the gauges peg. no dash lights, no crank, no nothing. other times, the car will start fine, run for 2 seconds and quit (which i know is the passlock) but sometimes when the gauges are going crazy, the trunk will pop for no apparent reason....... i replaced the ign. switch, because that was the most logical thing to replace.

anyone experience these things?