packing slip is not visible in select packing slip form to post the invoice after posting packing slip

Hi all,

packing slip is not visible in select packing slip form to post the invoice after posting the packing slip in dynamics ax-2009.

But packingslip id is visible in vendpackingslip trans table.

and AP is trying to match the packing slips and the total of the three separate receipts have been combined into one receipt

how can I find and resolve the issue

Once verify if any customization done around.