I see AMU... that means you're trying to use an AsicMiner Block Erupter. You can't mine on Middlecoin with that. It's a SHA256 only ASIC. You can only mine direct Bitcoin or other SHA-256 based coin pools. Middlecoin is a Scrypt based pool even though it outputs Bitcoin to users.
Basicallly you're trying to fit a square peg in a round hole. Not gonna work.
You should be using that USB miner to mine on BTCGuild or a Bitcoin P2Pool node.