I notice you accept namecoins. What version of the namecoin client are you running? I'm just checking to see if you are running the latest client which switches on merged mining at block 19,200 to ensure you don't end up on the wrong side of a chain fork.

How are you handling the issue whereby namecoin has a small hash rate and an attacker with >51% of the network can effectively deposit namecoins, trade for bitcoins, withdraw the bitcoins, then reverse the deposit?