We have a user that we configure the CRM 2011 Outlook add-in on and it works fine for awhile and then it just stops working. When it stops working, the ORG quick launch button in the Outlook Navigation disappears and Outlook thinks that CRM needs configured.
However, when you pull up the configuration wizard, the configuration is still there. If we remove the configuration in the wizard and re-add, the add-in will work again for a short period of time. Again, this is only happening to one of our users.
All of our users are running Outlook 2010 (14.0.6112.5000 64bit).
I don't know if it is the same, but several months ago I had a view that only one user was using. The view on the entity contained an error. Once I cleaned up the view the error went away. I don't know if it is the same issue, but it
is something you can check.