Might I just suggest that you separate the amount you are paying extra each month, and send it in a check marked "Principal only." If it is part of the total you pay - the mortgage company may just apply it to your next month's mortgage as part of principal and interest.

That is what Countrywide did anyway. They told me I would have to send in a separate check specificed for principal for it be treated that way.

Congrats on your place! Sounds like you got a great plan.