SD Order simulation is not working well

Hi experts,

I am trying to implement an order simulation function module for third party systems. Therefore I implemented an RFC function module which is calling  BAPI_SALESORDER_SIMULATE internaly.

Now I have the problem that in some cases the  BAPI_SALESORDER_SIMULATE is returning no result - in detail: no export order positions.

The error is very often "Address category does not exist" (Message class VP, number 700). But sometimes not error message is inside return table.

For this problem I found the SAP node 1487132.

So I call the function  SD_SALES_DOCUMENT_INIT before BAPI_SALESORDER_SIMULATE. Without any parameters.

The result is similiar. The order simulation is not working well all the time...

It seems if the order simulation is gone wrong one time, all following calls will also go wrong without erro message in return table. Are there any lock entries or something like this?

Has anybody else further ideas?

Regards

Christian