I'm sorry to hear that... ("even went to the extent of adding another account and then removing it")
Yes that's the section from where I removed the account that was seemingly causing the issue (I kept receiving notifications that some account needed fixing) - but I had 3 accounts.
I hope you find a way of fixing this issue (I must say that this way of handling the phone from within windows is useful) - I assume you cannot remove the one account and then re-add it, right?