Interesting thread and just thought I'd add my tuppence. Back in 1991 I went to England. At the time I was very self-conscious of my Irish accent, and the suspicion I felt of people watching me out the corner of their eye whan I was at the tube station or airport etc., and the sense I got of 'stay away from him, he's Irish'. Now it wasn't everywhere, and my guess is that the people that reacted like that suffered from cosmic xenophobia anyway. But it was there, as a definite feeling. Of course that was before the Ceasefire etc., and there were still signs everywhere about 'if you see anything suspicious...' etc., People I met on a personal basis seemd fine, perhaps at pains to prove they weren't biased. I probably got less flack than some of my friends, on account of my English surname (50% English family). I know many of my friends in those days got hassle at seaports, airports etc., and being forced to sign the PTA (the pink paper, we called it, Prevention of Terrorism Act form). One border official explained to my friend 'It's only because of the Irish problem, you see" My friend asked this guy if Northern irealnd was part of the UK, and of course the border official said it was, so my friend replied, "well, then, it seems to me to be more of an English problem than an Irish one" I don't know if he accidentally fell down a stairs after that one or not, but I believe he's still alive and well.

About 2002, up in Bushmills, an avowedly Loyalist town. The kerbside was still blue, white and red, The landlady in the B&B was nice enough, but back in town, lo and behold I couldn't get a bite to eat anywhere! Every cafe / restaurant I went to was 'just finished serving' or 'out of stock' (!) though I could see they evidently were not. But I guess my southern accent put them off. In the end, the good old chinese takeaway did the business.

Then I was over in Oxford one time to visit a friend (about 1998, maybe) and we all went for drinks in the pub with his work colleagues (English). They were all as nice as could be, and even at pains to show they were not anti-Irish, and some even searched hard in their minds to see if they had any Irish ancestry. I have to admit I was a bit bowled over and remember thinking "My God! It's gone hip to be Irish! The End must be Nigh!" It was all a bit of a turn around from the previous decade's experience.

I have quite a few good English friends and we share quite a laugh over Viz comic etc., But I must say I don't really like 'Irish' jokes a lot. One guy I know said 'you know why Irish jokes are so stupid? So English people will understand them' Now I think that wasn't very nice, but I could see where he was coming from. You do get an unthinking kind of person for whom the word 'Irish' is lazy shorthand for stupid, but often it just shows up their own ignorance. Liz Curtis wrote a very good book on the subject ("Nothing But the Same Old Story") and in it she recounts a typical example of this last kind of person: a British guy who'd gone on holidays and when he returned he developed his holiday snaps. Getting them back from the shop he discovered he had 24 close-ups of his left ear. "Must have been an Irish camera" he was quoted as saying in the local rag that bothered to report the story. Groan! Where do you start?
The tabloids have most to answer for in this regard, but they are soundly mocked by that excellent (and English) publication, Viz comic.