FTB Button changes (upcoming 2.0.6)

I’m reverting back to the 2.0.3 version of buttons. 2.0.4 and later use one large image for all buttons and CSS to handle rollovers. Buttons have two states: Normal and Active (the Bold button is considered active when the cursor is in the middle of bold text). Those two states are prepresented by CSS classes, each of which has a :hover state to handle button rollovers. The problem is that the buttons need to be updated regularly (every 50 milliseconds or so) to work, but IE takes a long time to switch CSS classes. Mozilla has no problem with this and it caches background images quite well. But IE was slowing to a crawl for some users, so I’m rolling back the changes to not do any dynamic CSS class switching.
I hate IE.