Custom theme misses some icons (for buttons)

Custom theme misses some icons (for buttons)

Hi,

I am using a custom theme. This theme was done with the ThemeRoller-Tool from the jquery-mobile-Site. But when using this theme, some icons are lost/wrong. Example:

<a href="index.html" data-role="button" data-icon="edit">My button</a>

With the original theme a pencil is shown. But with my custom theme, a "plus" is shown.

I am using:
<link rel="stylesheet" href="/css/my_theme.min.css" />
<link rel="stylesheet" href="http://code.jquery.com/mobile/1.2.0/jquery.mobile.structure-1.2.0.min.css" />
<script src="http://code.jquery.com/jquery-1.8.2.min.js"></script>
<script src="http://code.jquery.com/mobile/1.2.0/jquery.mobile-1.2.0.min.js"></script>

Am I wrong or is it a bug?