Crystal Reports Summing up a calculated sum field

Message

     I have a report that I need to sum up. The field I am summing is a field that is multiplying a percentage against a summed field. 

EX:

1.25
.50
____
1.75 * 90% = 1.575

1.50
.85
____
2.35 * 40% = .94

I need to sum up 1.575 + .94 = 2.52

This is the formula I am using for my individual line totals called Comm Amt 2:

({@% paid of amt due}*Sum ({@Comm Amt}, {CASH_RECEIPT_LINE.CHECK_ID}))/100

Next for the grand total (Comm Total)  I have:

whileprintingrecords;
shared numbervar CommTotal;
CommTotal:= CommTotal +{@Comm Amt 2};
CommTotal;

This works fine until the very last record. It adds it in again. Using the example above it would be:

1.575 + .94 + .94 = 3.455

I have a reset formula set up called: CommTotalReset:

whileprintingrecords;
shared numbervar CommTotal;
CommTotal=0;
CommTotal;

I have tried putting this at every level and it doesn't seem to make a difference.

How do I correct this? Any suggestions? I feel like I'm missing some small thing and just can't quite figure it out.

Thank you in advance for any help you can provide.