Put a suppression formula on the total - right-click, Format object, click on the formula button to the right of the Suppress checkbox. If this is always the last row on the report type in this:
Not OnLastRecord
This will suppress the total if the report is not on its last record.
If you need to show the total for a group rather than for the whole report, you'll enter somthing like this:
Not OnLastRecord and {table.group field} = next({table.group field})
This will suppress it for all but the last record for each group.
-Dell