we ran into an issue on HTC devices where CSS3 transitions would cause a "double password" box being displayed whenever a form was being displayed over the animations.
Basically the Android-created overlay would be drawn in the bottom of the screen, irrespective of where the actual HTML form markup was rendered.
Every time you typed in the password field, Android would update both boxes. Looks horrendous. It usually disappears after the input field loses focus...usually.
Since trying to force a style didn't work, we instead had to make sure the -webkit-backface-visibility was set to '' (instead of 'hidden'). whenever the input form as being shown.