During which search exactly are you wanting to invoke this? i.e Job Costing search (search for a job from the job screen)?
On purchase order lines,
creditor purchases lines
creditor payment lines
Aha! You need to add the forms involved (i.e. Purchase Orders) to the Forms tab of the plugin so the plugin knows when to fire!
Yes! It seems so obvious I'm sheepishly embarrassed.
That did the trick, thanks again for your awesome help.
Cheers

