I recently had a similar issue with the exact same symptoms as yours. Before dropping the Tranny, i figured I would replace the Master and Slave and to my luck, that fixed the issue. It was strange because I wasn't losing any fluid either.
Got any pics of the failed throwout?
"Stance: cuz goin fast cost money yo (n/m) - ZiNnYc 08/09/12 18:23:42"