OK, found part of the problem by doing the form by hand.
In the directions, it says that for exception option (B), only fill in the columns in line 17 (form DP-2210) for which an underpayment occurred. As a result, in my case, only column B has any values in it - column A, C, D are all empty. Because that's what the instructions say.
BUT, when the TurboTax "checks" are run, it finds these EMPTY cells in the DP-2210 form, and declares an ERROR and refuses to proceed until there is a value in the cell that the instructions tell you to LEAVE BLANK. So, I put in a value (that can then be ignored), and it WORKS by ignoring the value that isn't needed in the first place. The same think happens on line 18.
So when the check failed, I went back and manually edited the form to enter dates in row 17 and zero into row18 so the checks now pass. I just hope it's right - it seems to be based on my reading of the paper instructions and manually filling out the form by hand - so WHY did I pay for TurboTax?
