I received this response to my e-mail.
The points deducted from your account is in keeping with your
Milesource User Agreement that states the following,
"unredeemed AwardMiles will expire on December 31st of the second
calendar year following the calendar year such points are earned."
Due to this, AwardMiles(tm) earned in 2002 that had not been redeemed,
were removed from your account.
If they hadn't "upped" the amount of points needed to cash in just as I was nearing enough points, I would have cashed them in!