My own suspicion is that the high levels of inward investment to Ireland primed the asset bubble that developed there, Of course, the problem wasn't caused by the likes of Microsoft, Google etc. setting up their offices there but it probably did contribute to the irrational exuberance that keeps these bubbles growing.
It is a pretty scary situation they are in:
http://www.bbc.co.uk/blogs/thereporters/robertpeston/2010/11...