I just received a reply from AA as follows:

Dear Mr. XXXXXX:

Thank you for your email to Customer Relations.

I regret any misunderstanding regarding the $ 5.00 fee listed on the email
confirmation that was sent to you. The fee is actually a tax but this was charged when you had the original tickets issued last May. The information is stated on the new itinerary as it is applicable for the award you redeemed, however, it was not collected again when you had your tickets reissued.

I hope this clarifies this issue, however, if you would like to review further, please contact us by phone at 1-800-843-3000. We appreciate every opportunity to serve you.

This is an "outgoing only" email address. If you 'reply' to this message by simply selecting the reply button, we will not receive your additional comments. Please assist us in providing you with a timely response to any feedback you have for us by always sending us your email messages via AA.com at http://www.aa.com/customerrelations.

Sincerely,

Lisa Widmier
Customer Relations
American Airlines