I figured it out. When you want hidden rows included in the calculation you need to set the Override.FormulaRowIndexSource to FormulaRowIndexSource.Lstindex on the actual ultrawingrid.

I have implemented a calculated column and it works fine but it has rasied another issue. Is there any way to get the calcmanager to run it calculations against hidden records (hidden=true;)

I was assuming that the actual calcmanager iterated through the individual rows as part of the SUM function.  If it did, it would have a context for referencing an individual row and be able to evaluate my IF statement base on another column value in the same row,  rather than the whole column as you mentioned above.

I had better add my calculated column…….

Mike,

I hear what you are saying about adding the calculated field and summing it, but this is surely a long winded way…I basically have the same issue as tammy in that i am trying to carry out a conditional sum based on a simple expression. For instance on my text box the following will work

SUM([//gdBillCallsGrid/ConnectionBillCalls/CallCost])

but I cannot get the following to work

SUM(if([//gdBillCallsGrid/ConnectionBillCalls/CallCost] >10,[//gdBillCallsGrid/ConnectionBillCalls/CallCost],0))

I get "Incorrect type of argument or operand"