I really hope you didn't lead them to believe that you had the CMM experience. If so you might want to fess-up first thing, just to clear the air. Oh, and be prepared to continue your job search.
I would advise you to go to: http://www.sei.cmu.edu/cmm/cmm.html
And learn as much as possible about CMM and the level at which you should be performing. Learning their applications will be your first task, as well as making suggestions for improvement along the way.
Success is the ability to go from one failure to another with no loss of enthusiasm.
~ Winston Churchill ~