Button has wrong background on loading while focussed (BS theme)

Created by: janwalther

I have a button which should get disabled on click and change its text to "Loading ...". I use the button javascript function of Bootstrap for this behaviour. In connection with the Bootstrap theme the background is wrong.

To better show the behaviour I built a JSFiddle: http://jsfiddle.net/DX9Ma/1/ Click the button and you see the wrong background.