I recently upgraded to the new Yahoo Messenger from my BB Browser Homepage. But for some odd reason I get " Service Not Enabled for this Handheld" when I try to log in. My 8800 is on a BES and my 8830 is on a BIS and works. So I don't know if that is a factor. My question is, has anyone else with a 8820 on a BES had the same problem and if so, what is the solution? Thanks!!

Same problem here, looking for a solution. Sorry, I have no fix. Hopefully soon.

Same Prob! I'm assuming likely to be a problem withTCP settings for "The new AT&T".

I'm having the same issue with my TMO 8100. No one has any ideas on how to fix this?

I'm guessing that all of you are on AT&T. You need to download a service book that AT&T does not provide, so you have to download it form the Internet. Here are instructions from crackberry.com...
How-To: Use Yahoo IM 2.0 with AT&T - BlackBerry Forums at CrackBerry.com