Text cut off on Button in two column Grid

Using 1.3.1, see image above, the "Top Picks" is cut off in portrait view on an iPhone 5, landscape displays it fine.  As you can see there is plenty of space for the "Top Picks" between the icon and the start of the text.

What can cause this and what can fix it?

Here is my source:

1. <fieldset class="ui-grid-a">
2.                                 <div class="ui-block-a"><a id="btnSearch" href="search.aspx" data-icon="search" data-role="button">Search</a></div>
3.                                 <div class="ui-block-b"><a id="btnTopPicks" href="toppicks.aspx" data-icon="grid" data-role="button">Top Picks</a></div>
4. </fieldset>
   

• Topic Participants

• scott