"Don't smell me!"

***WARNING***  In some people's minds this might contain a little TMI...read at your own risk.

So I started potty training Jake a couple of months ago.  He has done pretty well with the peeing.  I don't think he's wet his underwear in a month or so.  Pooping is another story.  I can't convince him to do it on the potty.  He seems to actually be scared of it or something.  I seriously don't know what to do.  It is making me crazy...

The funniest thing is that when you ask him if he's poopy, he gets this little sad face and says, "Don't smell me."  He knows that's how we know that he's pooped--by the smell.  It kind-of breaks the tension of me being so frustrated because he just says it so funny.  As if not smelling it will make it go away...

Hopefully he figures it out soon.  I've tried everything.  I even took him to Target and told him I'd buy him anything he wants if he'll learn to poop on the potty, and even that didn't work.  I thought for sure the promise of a great big talking Lightning McQueen or Mater would do the trick, but no luck so far.  Any tips would be appreciated.  I didn't have this problem w/ the other 3...