Yah, if you find something that's IE 8 only, but works fine in IE 7, then you should report that to the IE team (I think they take their feedback on Connect, but I'm not totally sure). We're rendering the tag that tells IE 8 to render like IE 7, so if it doesn't work like IE 7, then it's their bug.
<meta http-equiv="X-UA-Compatible" content="IE=7" />