FI Substitution rule working only in Change mode.

Hi All

I'm running into a strange one. Hope y'all can guide me.

We're using a substitution rule via OBBH for all documents of type DR (call-up point 2).

For all line items with posting key 01, the substitution basically picks up a constant from the customer master and puts it in XREF3.

However, the substitution rule doesn't seem to be working.

I've activated the substitution rule, I've run the RGUGBR00 program. I've activated the "trace" and tried positing a document. From the trace display, I clearly see that the value is derived correctly. I can see that XREF3 has the constant value. However, when the document is "Saved", XREF3 is coming as blank.

There is only this one substitution rule in the system.

Another interesting thing is when I go in change mode, the substitution rule is working fine. If I go into FB02 for example and change anything .. say text.. and save the document, XREF3 has the value derived via the substitution rule.

I'm at loss of what needs to be done. Could anyone please guide me

Thanks

VH