issues with transferring correct retirement distribution code to PA state form

For some unknown reason, this year when I transfer my retirement income to the PA state return, it doesn't allow me to say that my state pension is NON-TAXABLE on my state return. I have not had this problem in previous years. I have gone back and "edited" the data for this 1099-R on the federal return (which the state return says I have to do), but it makes no difference; PA state software still thinks my non-taxable state pension is taxable by PA. Any suggestions ?