Problem with Version Call

Hi,

We have a Custom version of batch  R4311Z1I which calls the P4310 to create a Purchase order.

This batch program has a particular version of P4310  mentioned in the Processing options, which is VERSION1.

But when we execute the batch program, it is actually calling a different version VERSION2 and eventually Job ends in error.

Both VERSION1, VERSION2 exist in the environment. I need some hints on why these are happening:

1) Why the VERSION2 is called instead of VERSION1?

2) Why does the job end in error?

We have this problem only in our Production, but not in User testing Environment(UT) and Quality(QA) Environment. And also this happens only when there is some data to be processed in F4301Z1, F4311Z1. It does not happen when we don't have any data to be processed.