I've had the same experience, and judging from the number of posts about related issues here it seems a lot of others have too.
It just seems that there is no formal method (or if there is, then it isn't used much) for recording the fact that you were requested to present something at the station.
The result is that you turn up at the station and the big lad behind the counter makes you feel like you've done something stupid for doing what you were requested to do. The net effect is that people lose confidence in and respect for the Gardai because of repeated instances of this type of thing.
I would have a lot more respect for the force if things were more clear cut - you don't have your details on the road as you are required to do and you get fined, you don't have your NCT etc . . . and you get fined.
z