I believe it's caused by some people abusing the server, which slows it down. When a PHP script has been running for 60 seconds it times out, causing the 500 error you see.
~Callum
@stpvoice: Terminated.
qaiszz, what was your account terminated for? Whatever it was terminated for, I'm afraid there are no backups at our end - you will have to reupload your own backups.
~Callum