Problem with forwarding e-mail

I asked this question previously but received no responses. I probably failed to clearly identify the problem. I have upgraded to ML on two Macs (IMac and Macbook Pro) with no problems except the Macbook pro. Both computers have the latest updates on all programs and the disk utility has been run on them with no problems. When an e-mail is forwarded on the Macbook Pro and the address is clicked in the menue bar, the contact list is displayed. When a contact is highlighted, instead of inserting the name in the receipent line, a new window is created. Contact's can't be added to forwarded e-mail using the address bar. Other than that eveything is fine. This really does not bother me because I do not insert cotacts that way. My wife is about to have a fit because he is the one using this method. I would appreciate some advice if possible.