EndNote X3 is not compatible with Word 2010. Word 2010 users should upgrade to the most current version of EndNote available.
Important information for Mac users:
2/1/2013 EndNote's Cite While You Write function is experiencing compatibility problems with the latest Mountain Lion update (10.8.2). We will post in this space when the problem is resolved.
EndNote X5 has some compatibility problems with Mountain Lion. Specifically, you will need to use the Firefox browser if you want to export citations directly from library databases or Google Scholar into EndNote. You will also have compatibility problems when using the Cite While You Write function in Word. Please contact EndNote Technical Support to discuss how you can change your preferences in order to use Cite While You Write.