And funnily enough, it became an issue because someone knew that you shouldn't be driving on it after being resident for 12 months. And anyway, the IDP ceases to be valid after 3 years regardless of national law - so your admission that you've had one since September 2006 is enough to show that you're breaking the law, yet again.
No wonder you have such problems with the Polish police when you can't seem to stay within the law.
What kind of trouble should I have been in according to you- " the person who knows everything about everything"?
You should have been treated in accordance with the rules for someone who was driving without a valid licence. The fact you didn't - count yourself lucky. An expired IDP is the same as driving without a valid licence.
So.... now what happens?
Nothing much. You should go to your local police station to find out when your driving "year" ends - at the end of the "year", your record is wiped clean. You have 24 points a year to play with, so really - nothing to worry about. Even if you hit 24, you can take a course which removes 6 points - so really, drive freely.
The guys partner wrote 3 tickets to other drivers in the time it took mine to be completed for a comparison.
I think in all fairness, they may have been conducting additional checks on you. My suspicion is that they could have been waiting for confirmation of your residence - while they can check the criminal databases within seconds, I'm not so sure that they can check your residence status so quickly.
Either that, or the guy was just being awkward for the sake of it. Odd though, the Polish police don't like to keep people waiting around in general.