DOCUMENT_MAIN01 Badi is not getting triggered For ME22n

Hi Experts,

I'm new to ABAP Development . First of all, i'll let you know what my requirement is.

For a PO in ME22n, When i Add/ Change the Document , Vendor should get the alert regarding that.

So, i've done BADI Implementation for that.

The BADI what i've used is DOCUMENT_MAIN01`AFTER_DETERMINE_VALID_VERSION..

Now In ID1, it is working properly , means, that BADI is getting triggered when the following activities are done..

1. Selecting the PO line item and Clicking On ATTACHMENTS button

2. Adding / Changing / Deleting the Document

3. When Picking the document by choosing F4

But In my Client system, it is getting triggered only once , means , in that first case... To fulfil my requirement . it must get triggered rest of the cases...

How to solve this problem and what might be the reason for not getting triggered in my client system but working well in ID1.. ???

Thanks in Advance...