is it possible to change JQM's default icon? ( locally hosted files)

Question

I've asked this question here: changed jQuery Mobile's default icon set, work on browser, failed on device, but I still not able to solve it.

I locally hosted jQuery's CSS files. In the images folder, I changed the icons-18-white.png, and altered the default shape:

it works fine in Chrome. But when I build this on devices ( iPhone or Android), it's still pick up the old default icon.

First, I thought it is cache issue, but I've tried to clean the project, but does't work.

any suggestions?