What is the code in box 7 of the Form 1099-R from the 401(k)?
If the amount in box 1 is greater than the amount in box 5, is the difference shown in box 2a?
When entering this Form 1099-R into TurboTax, did you explicitly indicate that this distribution was rolled over to a Roth IRA (and not to a designated Roth account in the 401(k)?
