Man, that's just not enough information to even hazard a guess.
What kind of media?
What project settings?
What's your hardware setup?
What changed on your system recently?
well troubleshooting didn't help. but to answer the questions
.mov, .mp4, .mp3, .avi
default scratch disk is set for project folder
Mac OSX Tiger, 2 GB Ram, 120 GB Hard Drive
Is that a single 120GB HDD? If so, I'd not be surprised that MP4's did not play, or if they did, played smoothly.
As for CS3 working one day, but not the next, then something has likely changed. It could be as simple as an update to the OS killing a driver, or similar, or a HDD finally reaching its limit. Your task will be to try and find what changed. Were you on a PC, my first recommendation would be to update all Audio and Video drivers, and make sure to have the latest version of Apple QT installed. Not sure about drivers on the Mac-side of the street.
For NLE (Non Linear Editing) work, three physicall HDD's is about the min. recommended configuration.
Also, MP3's can be very problematic. I'd convert all of these to AAF (isn't that the Mac equivilent of WAV?), before Import. Far fewer problems.
thanks um but I noticed the same files work in after effects and encore so is it possible that something with premiere got corrupted? Would it be wise to just re install Premiere?
is it possible that something with premiere got corrupted? Would it be wise to just re install Premiere?
Possible, but before I looked at an uninstall/reinstall, I'd do a Repair Install first. If there are some broken/corrupted .dll's in PrPro, the Repair Insatll should take care of them for you and save a bunch of time.