I understand your frustration. Haven't been able to have my email synced in a few days and keep receiving the dumb error message from google talk. I wonder if it had to do with recently trying to sync my email calendar to an online calendar... hmmm.
Try this link... Edoceo's Blog: Google Apps, Talk / XMPP, Andriod Failures
I'm currently unchecking/disabling the sync associated with my primary mobile email and am going to wait a couple hours to see if it works. Otherwise, I do not know what else to do! Any other suggestions out there?