#div/0! error- but I'm not dividing!

I am currently receiving a #div/0! error in a sumif formula. However:

-I am not dividing in my formula
-The formula worked until today
-The formula is working in other places in my spreadsheet (my formula sums a certain range for a variety of cities, and each 'if' is a different city) only one is not working
-I have checked the entire range that I am trying to sum and do not find any other #div/0! errors

I would appreciate any help anyone can provide. Thanks!

=SUMIF('2011_Budget_Detail'!$G$2:$G$5683, "Turlock, CA", '2011_Budget_Detail'!AN$2:AN$5683)

You were right- I had the wrong filter on and just found the error. Thanks!!