It looks like you're not the only one who experienced this, lots of users too complained on their ANN thread^[1], you can make a post there too linking this thread. But as long as there's no response from TheQuin, this will not be cleared. Maybe this is just a technical excuse of not reflecting the new address's balance or what, lastly the site might be hacked that way, i hope it's no though. But as for the mean time, you can just wait and don't try to deposit again on the site.

[1] https://bitcointalk.org/index.php?topic=319540.9100