hmm, that's really strange. You can always root, back up the data that you want, factory reset, reroot, restore those apps/data then unroot. a bit of a pain, but it should work.
Let me recap here though so I am understanding (having a brain fart...)
There are TWO accounts listed on your phone. One you use and the other has since been deactivated (through the control panel on the desktop browser I am assuming).
It WON'T let you delete the account that is no longer active correct?
If so, did you try logging out of Talk and then logging in with the account you want as the main account?