Job/Customer Report problem

[tereque]

hi,
_**_
I have a problem with payment forwarding and how it is shown in Customer 
Report and/or Job Report
Let's say there is a Set as per below

_*Invoice#     Customer   Job   posted   payment*__*   value*_
Invoice-1 Customer1  Job1   1. Jan              1,000,-
payment 1.1 Customer1 Job1 10. Jan     -900.-
payment 1.2 Customer1 Job1            13. Jan     -150.-
Invoice-2    Customer1  Job2 15.Jan                300.-

So we have an overpay of 50.- for Invoice-1 (Job1) which gets forwarded 
to the next invoice for the same customer being posted. This Invoice-2 
(for a new Job2) is posted but no payment has been made yet

The customer report I make shows this fine. 2 Invoices, two payments. 
Total due of 250.-

Invoice-1     1. Jan  1,000.-
payment-1.1  10. Jan   -900.-
payment-1.2  13. Jan   -150.-
_Invoice-22   15. Jan    300.-_
*TOTAL due               250.-*

So far this is good. My problem comes up, when I look into Job reports. 
Payment-1.2 (150,-) is shown in both reports report for Job1 *and* 
report for Job2. Both times with the full payment value 150.-. So if I 
take add up the 'Total due' of both Job reports I get a wrong value.

Job Report-1 shows correctly a negative -50 (so the customer has  a 
credit of 50.-). Job Report-2 shows a 'Total due' of 150.- (which is 
invoice value 300.- minus 150.- of payment 1.2). it should be a 'Total 
due' of 250.-though because only 50.- had been overpaid for Invoice-1

any way to avoid this? This set of reports is great to make financial 
situation clear to customers (and yourself). But with this problem shwon 
above it is dificut to explain whats going on. It would be much clearer 
whether any Job Report would just shows payment that has been done 
related to the invoices of that report. Then you probably would mostly 
have an open balance on a Job report (credit or debit) but that would be 
at least clear. There is a credit from Job-1 and an open debit from 
Job-2. But as far as I know you can not suppress payment forwarding (or 
can you?). Any other way to solve this?

thanks, as always for your input