I don't think that changing your address to Ireland on .bomb will help you. I am a US citizen living in the UK and I have this every time I fly home on UA. It sees a US passport in the system and therefore assumes you must live in the US - and don't have the right to reside elsewhere.

It's a PITA as it stops OLCI as well as kiosk check-in and, if I have a domestic connection on the way back to the UK, seems to cause a degree of confusion with less well trained check in agents. This means I potentially lose upgrades when check in time is the decider.

I normally fly out of SFO and the international terminal agents there are well used to the problem as it affects a significant number of passengers on every flight to LHR. It seems UA IT can't get its rather small head around the issue (like having a field on the MP record showing right to reside elsewhere).