Ye found it, me bucko!
Congrats t'yer tribe! Ye best send a PM t'me right quick before those other scalliwags gets ahold o' ye winnings!
It's a good question that I've always wondered myself. The idea that there would be too many parodies if Isle Thing was included doesn't make sense, because The Food Album was ALL parodies. Also, they left off two other TV themed songs: George of the Jungle (cover) and Mr. Popeil (original). It's very possible that Scotti Bros just didn't like "Isle Thing" enough to put it on the album for some reason. As we know, Al was opposed to those compilation albums anyway and probably didn't have much say in their production.