As the enviable knowldgable QM advises, the phrase does mean 'Kiss my *&se' in Gaelic - it was the original name for Irish band The Pogues, but they changed it, in the interests of radio play for their records.
Andy - The Pogues had also been called The N*pple Erectors at one stage. That wouldn't have got them much airplay either. That was changed to The Nips.