Parkes, the fun with irregardless is due to the -less at the end, which comes around and bites the irr- at the beginning.
Irrecognizable is approved by no less an authority than the OED and has a history in print of over 150 years. I notice that you spell recognize with an "s" in spite of the OED's authority over the English language (just poking fun, I am aware of the problems in English social history and the intentional use and teaching of non-oxbridge language by most people).