Ultimate Tag Warrior is unsupported with WordPress 2.3. WordPress 2.3 does, however, have a thingy for importing UTW tags into WordPress.
You should do that (:
Then, you should have a look at WordPress Things. Some of them cover UTW functionality. There will be a plugin for the UTW template tags.. soon.. which should allow theme stuff to keep on working; but alas, there are still many kinks to iron out. Check back in a week for that one (: