I know that no other 9x9 squares can be constructed from my current database, but this database is incomplete. My arcane mathematical techniques lead me to believe that there is at least a fifty percent chance that another 9x9 square can be found from Web 2 words. Perhaps this square would meet all three criteria. If any reader has Web 2 or other large dictionary on compuer, please let me know. This time I won't have to suffer through long months of tension and ennui.
Technology marches on, making pioneering efforts seem crude and faintly amusing.
My current home computer can do the complete 9x9 search in one weekend.