Are your images in /www/images/? Do the jQuery Mobile icons exist in this directory (icons-18-white.png, etc)? Also, jQuery Mobile's CSS refers to the images with this path: background-image: url(images/icons-18-white.png);
I'm having same problem. I had the /www/images/icons-18-white.png. The icon show up on submit button but not on the listview. Also, the position of the icon is off the round circle in the submit button.