While searching the Limerick Ireland Genealogy database (http://www.limerickgenealogy.com/) for birth records on James Kenna found here in my database, I found a James McKenna born or baptized 14 May 1810. The record is from the St. Michael's (Roman Catholic) district in County Limerick. His father is listed as Michael McKenna and mother as Catherine Collopy. There was no other information on the transcribed record.
This could be the guy I am looking for (the date and location are matches), but I can't be sure since I don't know his mother or father's names.
(This search cost me 5 euro!!)