I have been wondering the same thing. I cannot use any of the Official viewers either. they just wont connect at all and crash back to desktop. I had to download firestorm just to play. in all honesty this makes linden labs look inept in my eyes.
i just downgraded my account to basic over this. i do not mind supporting the company if they were doing there job! but this s just stupid. you should not have to resort to using a 3rd party viewer to play the game !