Item Charge problem (average costing)

finder

Hi,

We have following problem in version 5.0 SP1 :
1. Make PO and post it for Item A with Amount 1000
2. Make SO and post it for the same item
Let's say that we use wrong customer by accident and we want to credit it.
3. Make Credit Memo for previous Sales document without Exact Cost Reversing
4. Make new SO and post the same item
At the moment everything looks OK. All value entries have Cost Amount 1000.-

5. Make PO with Charge(Item) for the same Item (for posted receipt) with amount 10000
Now program creates 3 new value entries:
1. Positive entry - PO with Charge(Item) value 10000
2. Negative entry - first SO (credited one) value -5000
3. Negative entry - second SO (correct one) value -5000

Now this charge(item) value has been divided to both SO but we needed to get it only for second SO otherwise customer statistic is very wrong. Does anyone have a good idea how to solve this situation.

Thanks in advance,
Anti