Assumiong you are referring to shared variable formulas...
1 - in general you do not want to do calculations in a header as they will only look at first detail row of that group.
2 - for group calculations using shared variables in general you need 3 formulas.
the first goes in the group header and sets the variable to 0 (or whatever your starting value should be)
the second goes in the detail section and does the row level calculations
the third goes in the group footer to display the final result for that group
Edited by DBlank - 24 Dec 2014 at 6:37am