Unfortunately, the BTCs have not appeared on the Blockexplorer yet. We will continue to check for your transfer daily and notify you when it is complete. ...
... When BTC is sent to another Mt.Gox address, the transfer is done instantly and will not appear on the BTC network.
These two statements of MtGox support are inconsistent. "The transaction will appear on the block chain." or "the transaction will not appear on the block chain".
That's because, likely due to lack of training, the first statement is wrong.
Plus the seller didn't give me a MtGox address he just gave me an address.
That doesn't mean that he didn't
give you a MtGox address.
He didn't know I was going to use MtGox to send the bitcoins. The seller claims to have not recieved the 11.1 bitcoins that I sent from MtGox but did receive the 5.9 bitcoins I sent from my wallet.
Likely because he's not logging into his MtGox account to verify this. Honestly, I would love it if the seller started posting here instead of you, because your obligation is complete.
MtGox: what is really happening? If I send bitcoins from my MtGox account there is a promise that the bitcoins will actually be sent. It doesn't appear to be that way.
sent. There's just no promise that the transfer will be sent to the blockchain if it can be processed internally at MtGox.
The internal sending mechanism works. I've tested it.