Summation box shows "0" despite ticking checkboxes

I'm having the same problem again. The export values for the check boxes are set to "1", but the end result doesn't add up in the summary box on the last page. (I am only using LOC at the moment)

I would be very grateful if someone could take a look please.

ETA I think part of the problem is that I have included fields in the calculation which don't actually exist (i.e. LOCB12.2 - so why are they showing as available to select?