They have turned their wallets off for all currencies, are experiencing intermittent problems with address generation/withdraws or they are blocking user accounts from everything but chatting..... I really hope it isn't the last one as that is theft !

Mercatox Exchange already have a bad rep on the Bitcointalk Forums and the OP hasn't been around since March, even scam accusations and threads about Mercatox locking accounts & holding funds due to "fraud"....