You say you have hundreds of files on your hard drive, what size is the hard drive? If it's only 80GB and you have lots of midi files on there, it is possible it is, or becoming full. I think I would try saving some of the files to Floppy, then delete these from the hard drive. If the malfunction ceases, that could be your problem.
Worth a try anyway.
Good luck!
Aud (U.K.)
[This message has been edited by Audrey Turner (edited 05-20-2006).]