Logic Constantly Crashing!!

Anyone got any thoughts or ideas on why it's crashing so much?

I can't even put a plug in on an instrument track without it crashing sometimes.

I have updated to Snow leopard 10.6.2 and it's still exactly the same.

Tom

I will try the disk permissions fix thing in utilities, hopefully that may help.

I am using 3rd party plug ins, all genuine ones, no cracks.

I haven't tried another soundcard because i don't have one, just the built in audio. I aqm currently using a presonus fire studio project, all updated to the latest firmware.

I haven't tried it on another hard drive either, i would imagine this would mean installing logic all over again on another hard drive which i don't have.

Quite often the audio drops out just randomly, sometimes as its playing back my song, sometimes when i press play, totally random.
Just now i was finding that when i went to insert rob papen blue plug in, it crashed, did this 3 times in a row, so i restarted my mac, then it was ok, but then the audio dropped and i got the popping/clicking after about 15 mins.

I have also noticed that nearly everytime i quit logic it doesn't quit, the project closes but the program doesn't quit, i have to force quit it.

Hope any of that helps, i have got the logic studio upgrade but i haven't installed it yet, i'm kind of scared that it will be a nightmare, maybe i'm just being paranoid.

I tried increasing the buffer size in logic to 1024 from 512 too, but that hasn't stopped my problems.

Thanks for any help and advice, like i say, logic has been perfect for me for years up until this last month or so.

Tom

that would make sense, i will go through and have a look for updates, i've got loads of plugins though, that is the only problem.