Poloniex - STEEM/SBD
STEEM is currently under maintenance or experiencing wallet/network issues. Deposits and withdrawals will remain disabled until a solution is found, which may require an update from the STEEM team. Any updates must be tested and audited before enabling.
^^ Think this will ever be fixed ?
They have been having problems for a long time. Best not to use Poloniex for Steem right now. Bittrex and Kraken may be better options.