Negative Quantity in Delivery - Run Time Error

Hello All
In our Production system, we got a run time error when we tried to process the delivery in both VL02N and Vl03N. When we looked at the table entry for that delivery, we had negative entry for the delivery quantity.

I checked the copy control functionality and the control data has been maintained as positive. Do you know what might be causing the negative qty in delivery and how to rectify it.

Our Delivery creation process.
The deliveries are created in the back ground. Apart from the standard delivery split conditions, we are also splitting the deliveries by Division by passing the value in the ZUKRL Field.

Runtime Errors DYNPRO_FIELD_CONVERSION
Date and Time 07/24/2013 11:30:47
Short text
Conversion error
What happened?
The current screen processing action was terminated since a situation
occurred where the application could not continue.
This is probably due to an error in the ABAP program or in the current
screen.
What can you do?
Note which actions and input led to the error.
For further help in handling the problem, contact your SAP administrator
.
You can use the ABAP dump analysis transaction ST22 to view and manage
termination messages, in particular for long term reference.

Error analysis
The program has been interrupted and cannot resume.
Program "SAPMV50A" attempted to display fields on screen 1102.
An error occurred during the conversion of this data.

Message was edited by: Jürgen L I attached the file from your mail