MS Excel error message

I have a user, that everytime he starts up MS Excel, he gets an error message that says Microsoft Visual Basic “Compile error in hidden module: AutoExecNew”, and when he closes Excel he gets another one that says Microsoft Visual Basic “Compile error in hidden module: DistMon”. Can anyone tell me where this error message is coming from? We’re using MS office 2003 standard. Is there something that I need to download?