cscott, upon reading your many posts I'm certain the error was yours. Isn't it funny that the same people seem to post that TWS is buggy and has order entry problems while the vast majority do not? The probabilities don't add up.
The audit trail doesn't show the execution. Like all the other threads with similar accusatory titles, I'd wager my house that the order was filled due to your lack of understanding or misuse of the TWS.