Just recently I have lost all access to my Yahoo account, Yahoo! IM and Yahoo! GO from my Personal Digital Assistant/Cell Phone (AT&T 8525). This seems to have occurred coincident with changes to security. If I establish a new Yahoo User ID then I have access to these services but my old ID fails. I think it has something to do with the way Yahoo is authentication the connecting device/system.

What can I do to restore my PDA/Cell phone access?