Someone out there has a ballot registered to me

UPDATE: PHOTOS ADDED

I just got my absentee voter packet for San Diego County, and I got this extra letter along with it:

"Dear Voter:

Our records show that you have been issued two ballots for the Presidential General Election November 2, 2004.

Voting twice constitutes a crime. Please sign the enclosed pink second ballot form and return it to us as soon as possible.

VOTE ONLY ONE OF YOUR BALLOTS

We appreciate your interest in voting, and hope you will feel free to contact us if you have any questions.

Sincerely,
(signed)
Maria Alvarado, Election Processing Supervisor
Absentee/Mail Ballot Section"

So, the obvious question remains...who the *$&# has my other ballot?! And how is a sissy little pink ballot form going to stop someone from casting another vote in my name?!