Error in a return for 2005 calculated by Proseries Software

I was just reviewing a clients return before finishing it up. Was wondering why he didn't have a taxable state refund. When the software moved the numbers from the Fed 1040 to the State 1040 the Fed Adj Gross was increased by $11266. I can't find anything in the return that comes close the this number. Guess I depended too much on technology. Don't know how I didn't see that error last year. I went back and opened last years return, and watched as I opened the state return...the amount he paid showed as the return opened and then it updated to show he should have had a refund. Now, I have to go back and do an amendment for him. I have checked the 5 returns before and after him but don't see a problem.