[MrX]

Simple sollution:

If your seat's occupied and the staff do nothing:

1) Full refund
or 2) No quibble Upgrade to first class.

Otherwise, they might as well scrap the reservations system.

Twice now, I have arrived on a Cork-Dublin train with the reservation system not powered up/working correctly and my seats have been occupied. We have either had to find other seats or ask people to move.

I've heard horror stories like a German teacher who had an entire coach booked for a full school tour. People removed the reserved seating notices and sat down, staff were unhelpful / non existant and she ended up having kids scattered throughout a busy train.
She got off and just laughed it off as "typically irish disorganisation" but was very unimpressed.