Quote from Thunderdog:
Actually, my guess is that marketsurfer engaged in an imaginary trade using his continuation chart and forgot that December became the front month today. Had he actually been long YM, I think it would have occurred to him that he couldn't exit his September contract at December contract prices. At the very least, he would have given his broker a good chuckle before he was set straight.
Of course, I'm just guessing here. Perhaps marketsurfer could provide some much needed detail...
P.S. You will recall that riskarb had once caught marketsurfer in an imaginary stock trade, where marketsurfer reported to have entered at a price that was never even hit.