System doesn't show VA03 from Document flow.

<Standard>

VA03 -> Document flow -> select sales order and press "Display document" button

System displays VA03 screen.

<Symptom>

ZVA03 -> Document flow -> select sales order and press "Display document" button

System displays ZVA03 screen. Not VA03!!

ZVA03 = a new transaction for customer based on VA03 with a transaction variant screen.

I have debagged and found system calls 'VA03' when pressing "Display document".

But system seems to hold the transaction variant screen and shows ZVA03.

I don't know the reason why system doesn't show 'VA03' screen despite of a standard function of Document flow.

How can system hold the transaction variant of ZVA03? (SAP memory? or anything else?)

Our customer nervously wants to get the reason for this symptom.

I have checked SAPMV45A / 4001 in SM51 and not been able to specify the coding about this transaction variant.

Could anyone advice me?

Takeru Miyagawa