Nonqualified Pension Plan i.e., an Amount in Box 11

My W-2 has an amount in Box 11.  There is a "PA" in box 15 and State ID.  Since PA does not tax pensions there is zero in Box 16 (State Wages) and zero in Box 17 (State Income Tax).  Turbo Tax prompted me to enter a state associated with this income so I entered "Pennsylvania".  When Turbo Tax does the final review it says that the state I entered does not match a state entered in Box 15.  I reentered the W-2 and put "PA" in Box 15 but the final review still says it can't match a state in Box 15.  The only way I could pass the review is if I enter PA in Box 15 and enter an amount in Box 16, but I don't want an amount in Box 16 if PA doesn't tax this amount.  How can I keep the W-2 data matching what is on the form  (no amount in Box 16) but still pass the final review?