Error summing product of group variable

[byron.ullauri]

I have a group on accounts.

(Field Amount)  -  the amount coming in for an account

All BigDecimal types

(Variable A) -     I have a variable set to sum Amount per account, reset on group, and display a total for that group.

(Variable B) -     Another variable takes this sum (Variable A) and converts it to USD by multiplying it to a rate. 

(Variable C) -     Finally, the variable causing the error sums on this converted currency product variable (Variable B) for a USD total. 

 

Basically, for each member of this accounts group, I have to show (Variable A) and (Variable C), which are both found in the Group Header.

I put (Variable C) in the Summary Band to show the sum total of (Variable B) .

All this is in a subreport. (Variable B) is fine but (Variable C) comes up with a ridiculously high sum.

Any suggestions on what to try and change?