I'm going to admit I did something really dumb in hopes of saving someone else some time.
I followed the instructions in Steve's blog rather roughly to scaffold my own model classes. And I modified the layout page to display my new controllers and checked that they were in place and correct.
So, I typed the controller and action at the command line.
Still an error.
I put it aside as I was prepping for an MVC extensibilty talk. Somewhere in that timeframe I ran across one of Steve's posts that said more or less "based on feedback we decided to pluralize the controller names".
Oops. Oh yes, now I notice. I was thinking and typing "Customer" when a little "s" had sneaked in behind!
Things work much better when you spell the controller name correctly ;-)