I noticed something weird; As i'm a mac user and don't have IE i check my websites on ierenderer.
In IE9 everything looks as it should be (attached). but in IE8 everything disappears except for the menu.
Now i wondered what would happen if i would just use the zen theme; and it gives a very weird results in versions lower then IE9.
Does this mean the 5.x branch doesn't support anything below IE9 anymore? Or is there a fix css file like in 3.x