I have been to Both Northern Ireland and Eire on many occassions, and only once ever felt even in the slightest bit uncomfortable…
Loaded At Warren Point
This was when we had just completed a move of 10 very large and heavy peices of a new cement works from Warrenpoint to near Derrylin, the setting up and movement of the peices took 6 days, on the 7th day we unloaded and went to the local pub for a meal and a few beers, the local abnormal load lads (from Martrain) all went home leaving the 6 UK registered trucks all parked up in the middle of this small village.
en route following one of the Martrain lads
The Biggest Peice… waiting at Derrylin
In the pub we ordered a meal each, however the meals were huge and each came with a seperate huge basket of chips, way too many for us all to eat so we asked the landlord to pass them out amongst the other customers… no point in them going to waste
A group of lads at the bar started to create, making very loud statements so we could hear about how it was bad enough to have to drink in the bar when “Brits” were in, and how they didnt need “Charity " from the likes of” those" 
Within a few moments a few of the local older men “requested” that these young lads apologised to us, and suggested that they went to another bar down the road… as they were leaving one of the older men took a basket of chips over and made each of them eat one before they left 
the landlord then came over with a free drink for us all , apologised himself for the young lads behaviour, and said that the NEXT drink would be bought for us by the young lads whi had just left , however they wouldnt know they had bought them until the next time they came in and he presented them with the bill 
We did say that is wasnt needed, and we didnt want him to get any trouble because of us… to which he smiled and told us that there wouldnt be any trouble and they would pay up no problem,
We ended up having a cracking night with the locals, there was some urine extracting on both sides , but all in good humour and we were told we were welcome back at any time… 
There is also the tale of the 2 weeks I spent placing into and then removing a 2000 tonne crane from a refinery at Whitegates near Cork, and the amazing never shut pub and Chip shop… but I wll tell that another time
copied from the Euro Forum
