21227 Flash 8 Upload 500 Error

Hi, I have a flash 8 Uploader script for mp3 files. When intalled on some servers and I try to upload mp3 files I get "HTTPError" filename.mp3.500 P.S. When the script does uploaded successfully it writes and xml playlist and also an mysql entery, so experience with these languages is an asset. Alos have .fla source For this project I'd like to get this working no matter what server the script is on. Looking in online forums, this seems to be a common error. Thanks