You can create just write a formula that will take the sum of the two fields and return the sum. You don't have to place the two fields on the report, just place the new formula.

Your formula will have to check whether the field is null or not to handle the case where some records only have one field.

EDIT: I just remembered that you wanted a summary. You can probably just summarize the new formula. Otherwise, if not, you would have to write another formula to summarize it.

Edited by Keikoku - 08 Mar 2011 at 3:13am