Hi Len,



I am in complete and total sympathy with your situation.  I receive students in my Freshman Comp courses who have graduated from HS without a bit of grammar instruction.  I can't talk to them about some of their problem areas because we don't have a shared set of terms and concepts, so I teach them the grammar that they need for the writing classroom.  



If you want to teach students to recognize an IO, show them the two ways that it can be expressed and then have them test candidates to see if they can change it:



I gave the ball to John.  >>  I gave John the ball.  Either one works fine--it's an IO.



"I rolled the stone to the wall" >> *I rolled the wall the stone.  This one doesn't work, so it isn't an IO.



Having said that, I typically do not spend time on the IO in my composition class because students rarely have a problem with it.  Perhaps it is useful in your analysis of literature to teach the distinction--I can't speak to that.  But comp. students don't need it. ( I certainly go into it and the form vs. function distinction that Herb so accurately detailed in my Advanced Grammar class, which is populated mainly by future English teachers.)



John