Transaction Form-WHEN-VALIDATE-RECORD trigger for TCMI_HEADER block firing only once in R12

 In transaction form under TCMI_HEADER block the WHEN-VALIDATE-RECORD trigger firing only once.

Am creating a new record and as required,the above trigger is firing and when am saving the record,it is not firing.which is working fine in 11i.

I handled the trigger in custom.pll.

For this I disabled all form rules on the form,and kept only one rule for WHEN-VALIDATE-RECORD for TCMI_HEADER block.and kept a message in the actions.For this scenario also,the trigger is firing only once.

Can someone help on this.

Thanks in advance,

Best regds,

Sree.