OS X 10.5.6. As long as I've had 10.5, OS X has constantly failed to open files with the correct program. The worst offender is iTunes, which seems to keep setting itself to be the default application for .m4v and audio files. Archive Utility also keeps going back to being the default for opening .zip archives and .tar.gz files. I think it's getting reset on reboot. I've gone got get info and clicked the Change All button, and tried the Default Apps preference pane, but it doesn't work. I've repaired permissions and reset PRAM.