Has it worked before on this copy of Word or is this a fresh install?
If it has worked before, can you still insert new sources through the
'Insert Citation', 'Add New Source...' option? Or is that disabled as well?
Although the tools should be working when you handle Word 2003 or earlier
documents (the result will be static text, but they should work), ensure
that you are working with a Word 2007 docx document.
If this is a fresh install, it is most likely that this was an installation
error. I suggest you uninstall and reinstall office 2007 (repairing does not
seem to help if it was an installation error).
Yves
