problem with unformatting citations

I’m experiencing a problem with EndNote X in combination with Word 2003.  When I select “unformat citations”, Endnote unformats most, but not all of the citations.  Some are left formatted (that is, if I put my cursor on them they have that greyed-box look).  No matter how I try to select the citation, Endnote will not unformat it. 

I’ve searched this forum for the answer, but no luck.  Does anyone have any suggestions? 

Is it possible that the word document migrated platforms at some point? see:

http://forums.thomsonscientific.com/ts/board/message?board.id=en-howto&message.id=21