button 'refresh' and hover

button 'refresh' and hover

below is html 

  1. <div data-role="content">
  2. <div style="width:250px">
  3. <input type="button" data-theme="e" value="data-theme='e'" id="testButton1"/>
  4. </div>
  5. <div style="width:250px">
  6. <input type="button" data-theme="b" value="data-theme='b'" id="testButton2"/>
  7. </div>
  8. </div>
changing the button theme as below

$("#testButton1").buttonMarkup({ theme: "b" }).button("refresh")
(This code can be directly tried from chrome/ff console)

it changes the theme.. but when I hover the button it returns to old theme.
And trying to change theme again wont work at all.

I knowh ow to change themes by directly changing underlying css classes.
But is above 'refresh' method supposed to work? or a bug?