I had the HUD update problem aswell, when i installed the 3.00 beta 21. Due to some other problems with postgres I deleted beta 21, reinstalled the 3.00 build 3 (incl. postgres) and then installed the beta 21. Now the problem is gone. HUD updates all players on all tables.
Dunno if its any good to you, but until a new version of PT3 hits the stores u may try this...
Edit: Btw I have to put in screen name EVERY TIME i start PT3?? It does not remember screen name?