Does this recent thread help?
http://community.thomsonreuters.com/t5/EndNote-How-To/Your-add-in-isn-t-compatible-with-this-version-of-Word/m-p/132195/highlight/true#M24176
or this one:
http://community.thomsonreuters.com/t5/EndNote-How-To/I-want-to-Uninstall-this-ASAP/m-p/129534/highlight/true#M23307