Im on the west coast, I rarely see anything for PA. But I know lots of non resident states do compute tax on ALL income then use a ratio % to compute the tax on it. So if the return had 100,000 but only 25000 was state income, theyd compute the tax on 100k but then the total tax theyd discount down to 25% of the total tax.....awkward explanation, I know, but could that be whats happening?