Help with Clearing Local and Document Currency

Question

I'm looking at the transactions below.
DocumentNo     Type     Clrng doc.     Period     PK     Doc. Date     DC Cur     DC Curr     loc.cur.     LCurr
100012081     SA     100012083     009     50     19/08/2009     -1,000.00     EUR     -865.50     GBP
100012082     SA     100012083     009     40     19/08/2009     865.50     GBP     865.50     GBP
I have two difference document currencies.  When I clear the document the posting is as below.
DocumentNo     Type     Clrng doc.     Period     PK     Doc. Date     DC Cur     DC Curr     loc.cur.     LCurr
100012083     AB     100012083     009     40     19/08/2009     865.50     GBP     865.50     GBP
100012083     AB     100012083     009     50     19/08/2009     -865.50     GBP     -865.50     GBP
Document Currency above is not cleared to zero for EURO or GBP...
My questions is why when clearing two different line items in two different documents. The balance on the document currency does not come back to zero.
I would have expect to see the following.
DocumentNo     Type     Clrng doc.     Period     PK     Doc. Date     DC Cur     DC Curr     loc.cur.     LCurr
100012083     AB     100012083     009     40     19/08/2009     1,000.00     EUR     865.50     GBP
100012083     AB     100012083     009     50     19/08/2009     -865.50     GBP     -865.50     GBP
Which would result in the Document Currecny being Zero in both Euro's and GBP and Local Cleared.

Answer 1

The posting you are expecting to see cannot be achieved in SAP because document currency is at accounting document header level and it applies to all line items in that document.  In short, document currency has to be the same in all line items.  You most likely have "No forex rate diff. when clearing in LC" checkbox checked in your company code global parameters (OBY6).  If you remove that, system will not be able to post the entry it posted (doc. no. 100012083) unless you configure exchange rate diff. account determination in OB09.