The Internet Movie Database is a great site. I was just perusing the entry for Alan Smithee and came across this bit of trivia:

The DGA decided that the name got so much exposure from the film An Alan Smithee Film: Burn Hollywood Burn that it was no longer an effective alias; the film Supernova was the first "post-Smithee" film.

Thus, the new alias is now Thomas Lee according to the Trivia for Supernova.