Revoked SES with account assignment distributed by quantity cannot be modified or deleted

Hi All

I have users who are posting service entry sheet with the account assignment distributed

on a quantity basis across multiple maintenance orders.  The acceptance works perfectly but we are having problems if a correction or cancellation is required.

The service acceptance can be revoked successfully but afterwards it is not possible to change the service quantity or to delete the service entry sheet.  When we try we receive an ABAP runtime error:

Runtime Errors         COMPUTE_BCD_OVERFLOW
Exception              CX_SY_ARITHMETIC_OVERFLOW
Date and Time          08.07.2014 14:25:12

Short text
     Overflow during the arithmetical operation (type P) in program

What happened?
     Error in the ABAP Application Program

     The current ABAP program "CL_EX_MMSRV_ACC_DIST_SAP======CP" had to be
      terminated because it has
     come across a statement that unfortunately cannot be executed.

What can you do?
     Note down which actions and inputs caused the error.

     To process the problem further, contact you SAP system
     administrator.

     Using Transaction ST22 for ABAP Dump Analysis, you can look
     at and manage termination messages, and you can also
     keep them for a long time.

Error analysis
     An exception occurred that is explained in detail below.
     The exception, which is assigned to class 'CX_SY_ARITHMETIC_OVERFLOW', was not
      caught in
     procedure "IF_EX_MMSRV_ACC_DIST_SAP~DISTRIBUTE_ACC_ASSIGNMENTS" "(METHOD)", nor
      was it propagated by a RAISING clause.
     Since the caller of the procedure could not have anticipated that the
     exception would occur, the current program is terminated.
     The reason for the exception is:
     An overflow was discovered in an ongoing arithmetical operation with
     operands of type P. Possible causes are:

     1. The result field of type P is too small for the result.

     2. The result or a intermediate result has more than 31 decimal places.

This problem does not occur if I run the same scenario any of the following variations so I'm confident the problem is related to the account assignment distribution by quantity:

• Single account assignment
• Distributed account assignment via percentage
• No service acceptance/revoke has been posted

There are ways to get around the problem but I'm trying to find a SAP Note that may be relevant.  I haven't had any luck yet.  Does this problem ring a bell with anybody who might be able to point me towards an appropriate note?

Thanks

Robyn