Why are all these older losses still pending? Has this address figured out how to block losses from appearing in the block chain, or is there a bug?
All good questions. None of which I'm able to answer.
I looked at the history of that address on the satoshidice site:
http://www.satoshidice.com/lookup.php?tx=18pEcNu&limit=2000&min_bet=0&status=ALLI tried to see the last 2000 bets from that address but the site only lets me see 1000 bets.
Of those 1000 bets, 660 are "unknown" and only 340 are "confirmed". The breakdown is as follows:
unknown: (660 bets, stake 5275.0, return 3367.47381977, profit -1907.52618023)
confirmed: (340 bets, stake 2727.55, return 2946.78077572, profit 219.23077572)
So it is indeed the case that the cancelled bets were net losers, and the confirmed bets were net winners. What's not clear is whether that's by accident or by design. It certainly is interesting though.