I have the same thing happening. I actually have 2 admin payments and a reserved slot payment. I know mine happened when I was playing and my admin expired at midnight, so i switched over and made a payment. I thought it would applie to my account, but instead it started a new subscription.

No biggie, but Zero I will be canceling all subscriptions. I think I have admin through Febuary of 2012 now so I should be good for awhile.