It appears that Poloniex is not allowing Steem withdrawls (not sure about deposits). This includes SBD.
I have just deposited several other cryptos and traded these for Steem, yet when I tried to withdraw it says 'Temporarily disabled'.
I do not leave funds on exchanges after a loss at Mt Gox, so I have had to trade back to btc and withdraw (which is still pending after 30 mins).
I hope they solve this issue soon as I wanted to buy in. Hopefully it will be resolved shortly.