why is first name showing up in parenthetical citation?

I am using Endnote X3, MS XP Pro SP3, and MS Word 2003 SP2.  I’ve been using Endnote for a few months and this is the first time I’ve had this problem.  When I insert two of my references, the parenthetical citation includes the first name of the first author as follows:

(Robert Haveman & Wolfe, 1994; Robert Haveman & Wolfe, 1995)

What can I do to get rid of the first name?  I delete it and it comes back.  I also tried deleting the reference from my document and Endnote, reentering it into Endnote and then reinserting the reference into my document.  I have also closed and reopened Endnote and Word to see if it was a temporary bug.  No dice.

Please let me know if you have any advice.

P.S. It is cited properly in the reference list:

Haveman, R., & Wolfe, B. (1994). Succeeding generations: On the effects of investments in children. New York: Russell Sage Foundation Publications.

Haveman, R., & Wolfe, B. (1995). The determinants of children’s attainments: A review of methods and findings. Journal of Economic Literature, 33(4), 1829-1878.

This is usually caused by a subtle difference between the way the first author is listed in the two references, so it thinks they are two different authors that need to be “disambugated” (if that is a word).  An extra space or two initials without a space between them or something like that.  It is easiest rectified by copy and pasting the author from one of the records to replace it in the other.  As long as it isn’t a change in the spelling of the author’s surname, reformatting should fix it.  If it doesn’t try removing that reference again and reinserting it.  This should fix the problem.