Thanks everyone for the responses!

TT is spitting out ES vouchers because it thinks, based on what you've told it and certain assumptions, that you have a prepayment problem for 2007.

I think the "certain assumptions" is what was doing it. I went back and used the W4 calculator, and it had plugged in all sorts of projections for this year. Apparently I get a big raise, and our mortgage gets paid off, since our interest deduction was cut in half. We're also going to be surprisingly healthy, with few medical bills. What a great year! So, in any case, based on that, our taxes were going to be a lot higher next year.

I fixed the assumptions to more normal numbers, and the calculator said to keep our withholdings where they are.

Now, off to spend my refund money on a printer so I can mail in my state forms! Hmm... or maybe I could just pick up the paper forms at the revenue office for free. :)

Thanks again!