Hello, everyone.
Please note that checking the support email -- poloniex@gmail.com -- is higher priority than checking this thread.
Deposit/withdrawal problems. The wallet server is getting bogged down with the recent massive increase in activity. It's out of memory. I've ordered a much better server with twice the memory and room to expand.
Let me explain why people are getting things like "PENDING: 15 of 3 confirmations." The deposit/withdrawal daemon runs in a sequence. First, it checks the transactions in the wallets, one after the other, updating confirmations of pending deposits and adding new deposits. Next, it checks to see which deposits have enough confirmations and credits accounts. Then it processes withdrawals, one after the other.
The daemon is on a timer--it restarts every n seconds. Sometimes, something massively slows down the process, usually a wallet taking forever to respond. If things slow down enough, the daemon will restart before it has finished the entire process. You'll get "PENDING: 15 of 3 confirmations" if it never gets to the second step, namely crediting deposits with sufficient confirmations. Withdrawal delays happen for the same reason.
Developers among us will no doubt see right away how this can be improved--multithreading. I'll work on that soon, before any new market additions.
I promise, it's a very high priority to avoid Cryptsy-like deposit/withdrawal nightmares.