Hi I'm working on a workflow and I'm trying to set a field in the current item to a value calculated. Im trying to do this:
Calculate Current Item:GP Instance Run Count plus 1 (output to Variable: temp)
then Set GP Instance Run Count to Variable: temp
But in the drop down menu of the set action the field GP Instance Run Count doesn't show up. This is not the first time SPD does this. It sometimes hides random fields, and I don't know what to do...

You can see int the image above that I was able to access GP Instance Run Count in the previous action
GP Instance Run Countdefined? – Per Jakobsen Jun 5 '12 at 8:52