I am running Ubuntu 12.04 and I uninstalled telepathy-gabble using
sudo apt-get remove telepathy-gabble
This removed functionality in Gtalk and Facebook in Empathy.

I restarted and tried to reinstall it using
sudo apt-get install telepathy-gabble
There were no error during these processes. I restarted and Empathy was successful in connecting to Gtalk, but it gave the error in this post's title: "Disconnected - This account is already connected to the server"

I've tried removing and redoing this all over again, I've tried adding a domain to my username, I've tried restarting, I've tried killing every Empathy process I could find. I don't have that much experience using Ubuntu, but I know the basics. Any help would be very much appreciated.