I use yahoo small business for my business and was anticipating the ability to access all of my email folders with the new update. It synced fine right after setting up the account again but it wouldn't refresh. It just kept saying my login credentials were wrong. it took me about 20 minutes to realize the incoming and outgoing server info was incorrect. It should be palm.imap.bizmail.yahoo.com. The difference is bizmail instead of mail. Now it works smoothly and without error.

if your yahoo small business account isn't syncing check the servers.