Problems with Backup

[orthodoc]

I am having a problem using Backup (comes with .mac account). When i try to run backup, I receive an error. It gets to the finding files to backup screen, then I get a window that pops up and says "Internal system error: an unrecoverable internal error has occured"

anybody know what the prob might be? I called apple, and they were no help at all.

thanks in advance