There is a slight issue in the CSS for JQM 1.3 RC1
some of the icons for the buttons are not properly aligned. and some are not showing when viewing on mobile device. I am not sure if its just for Android, but on Desktop, it looks normal but on Android, the icons are not centered
Just curious - it looks like you are hosting the files locally. Do you also include the image folder in the correct directory? That is important. Normall that is the problem, but it's strange that you can even see the arrow on the back if that's the case.
Anyway, without seeing it or giving us an example it's very hard to help. Need more information/code/example.
As already alluded you may be hosting jQM files locally. If you look in the jQM css file you will see references to :url(images/....). If you would like your app to work without editing the CSS file, then place the images that come with the following zip file into images sub-folder - where images is in the same folder as the css file.
If you have the icons elsewhere then edit the CSS file to point there.
I had the same/similar problem when testing an app I had written for jqm 1.2.0 and was upgrading to 1.3.0-rc1. On several bars and buttons the icon would appear with the symbol positioned in the top-left of the enclosing circle instead of centered. I had the issue with Chrome browser. I spent some time checking my icon files, and CSS. I then tested with a fresh install of Chrome on a different computer, and saw that all was well. After "Tools -> clear browsing data -> for all time (with everything checked)" and restarting Chrome, the problem was resolved.