I believe I have found a bug in 5.0.12. Normally when you click on an email to view it and then click click the email sender, you get options such as add to contacts, view URL, etc. Since the upgrade to version 5.0.12, this is not working on either FF or IE from multiple machines. I have attached a screenshot with the error from firebug. This only happens, when you have the IM enabled for the user.