> Consider it this way: Why doesn't the Coyote ever catch the Roadrunner? 

For him to do so would lead to circumstances that couldn't fit into 
Looneytunes.

He did once. ^_^  It was in a Christmas special.  Unfortunately, due to a 
pipe and a bizarre set of physics, the Coyote was only 8 inches tall. ^_^
But he caught the roadrunner.

--SG
--"OK, wise guys.  You always wanted me to catch him...*now* what do I do?"