Northern Ireland is NOT part of Ireland, it is part of the UK.
I know that Wikipedia is not always a trusted source of
information, but this page is pretty accurate:
http://en.wikipedia.org/wiki/Northern_Ireland
Unfortunately or fortunately, depending on one's point of view, by
international convention (meaning that all parties were in agreement at
the time of signing) Ireland's country code is IE. Ireland was part of
this agreement.
Marc
I forgot the link:
http://www.iso.org/iso/english_country_names_and_code_elements
Cheers
Marc