Why is turbotax saying I owe money from withdrawing Roth IRA contributions (not dividends)? My 1099-R says the taxable amount (2a) is $0.

Box 2b) says "Taxable amount not determined."  I can only assume this is because my bank moved all mutual funds to another financial institution this year.  This happened after I made the withdraw, but the 1099-R came from the new institution.  The old institution was quite clear that the money I withdrew was less than I had contributed.  Incidentally, I used the money to purchase a house (but not a first house).