There is no solution to the compatibility issue with Word 2010 and Endnote x3 or x2. We just have to wait for Endnote to fix the problem. Word 2010 works awesome without Endnote addin. However, I tried using Reference Manager 11 and surprisingly it works with Word 2010. Although I do not have Referece Manager 12, I would expect it to work with Word 2010 as well.