Outlook Rules issue using OFFICE 2011

I am a new MAC user and recently purchased a MACBOOK PRO w/Lion and I installed MS OFFICE 2011. I like to organize my mail into folders and have fairly good experience with using rules. The problem I am having now is that messages are going into the correct folders per my rules but the messages are being constantly duplicated each day in each folder so I have dozens of duplicated messages in each folder. I have the mail imaped using my gmail account. No sure if this is some synch problem that I can correct or if there is some other instruction I should be making in the rules.