Outlook 2003 Rules vs 2000

I recently upgrade a user from Outlook 2K to Outlook 2003. this user has a main email address and 2 alias's I have the mailbox on and Exchange 2003 server. She had rules that if an email came in to an alias it would be forwarded to another user. and the rules worked fine. I upgraded her to Outlook 2003 and now any mail sent to her main email address get forwarded as if it is the alias being forwared. I checked and her main email address is not in the rule, only the alias.
How can I get rules to work when they are going to an alias?
Thanks
Sam