Thank you both for the very helpful input.
Thank you so much for the replacement code! The problem is solved.
Thank you so much for the advice on modifying theme files. Lesson learned. How do I download a new copy of the theme? Don’t I have to start a new web site to do that?
Did anyone figure this out? I am having the same trouble with the Twenty Twelve menu on my handheld. I see that Jimmy had changed his footer, which is something I have tried to do. Is it possible that messing with the footer php can cause this problem?