Poloniex Support just contacted me. They're looking into it. I just had to provide some additional information for the support tech to track it down. Hopefully this will get resolved today or tomorrow. I'll keep you posted.
https://steemd.com/tx/df57589c38aef09d2c0d2feb54c072f05415aa4b
RE: Warning: Poloniex Lost My Money - 338 STEEM Gone - Poof!