https://bitcointalk.org/index.php?topic=248246.0

Its the way bitcoin handles "change". You'll see all coins sent to that address, will be sent back to the ponzi address when they are needed...

Basically, the input was 0.5 and that needed to be split - but input transactions cant be split, so some repayments were made and bitcoin needed to do something with the remainder of the 0.5, so it creates a hidden address which is essential a part of the ponzi address.

Thanks for the vote of confidence though.