<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by Rudi:
don't ly - your passport could have been found (and reported to be found) in the USA in the meantime ...</font>
If someone checked Irish immigration records and it showed that you didn't enter with the US passport, you could be suspected of being bin Laden's Philadelphia consul general and have your whole life turned upside down.
Although easier said than done, it's helpful to be organized in life and keep papers in their designated place.