I agree w/ Tobra, seems like the Title Company is on the hook now IF the title ins. policy stated the taxes were paid. Pull out the policy and read it thoroughly.
Otherwise, they are your responsibility. Hopefully your escrow agent is a stand-up person and fixes your problem as promised.
Just my opinion, and I agree that you should get professional advice.
edit: This may be helpful!:
http://www.thinkglink.com/Title_Insurance.htm
Best,
Kurt