IE8 Problems with tabs and tooltips

hello together

The tabs and tooltips [?] On my form is not displayed correctly in IE8. In firefox does both.

Does anyone know the problem?
Thank you

URL: http://web146.122.hosttech.eu/spass-am-nass/free-extensions/anmeldung-v4.html

CSS-Code

dl.tabs {
	float: left;
	margin-bottom: -1px;
	background-color: rgb(80, 160, 240);
	background-color: rgba(80, 160, 240, 0.7);
}
dl.tabs dt.tabs {
	float: left;
	margin-right: 6px;
	padding: 4px 10px;
}
dl.tabs dt:hover {
	background-color: rgb(60, 140, 220);
	background-color: rgba(60, 140, 220, 0.7);
}
dl.tabs dt.open {
	background-color: rgb(60, 140, 220);
	background-color: rgba(60, 140, 220, 0.7);
}
dl.tabs dt.tabs h3 {
	margin: 0;
	font-size: 1.1em;
}
dl.tabs dt.tabs h3 a {
	color: #fff;
	font-weight: bold;
}
dl.tabs dt.open h3 a,
dl.tabs dt.tabs h3 a:hover {
	text-decoration: none;
}
dl.tabs dt.open h3 a {
	font-weight: bold;
}
div.current dd.tabs {
	margin-left: 0;
	margin-bottom: 10px;
	padding: 10px;
	width: 85%;
	clear: both;
	border: 1px solid rgb(80, 160, 240);
}

Hi The_Surfman,

What exactly is the problem. IE11 looks OK and so does IE11 in IE8 emulation mode. I can see a problem in IE10 Emulation mode - that seems to result from the FormCheck code not handling the included <style> tags correctly* - we've seen that bug before with FireFox (but not IE).

Bob

* It looks for a value for the src attribute and there isn't one.

It looks like this and the tooltip will not be displayed when the mouse goes over.
[attachment=1]tabs.png[/attachment]

The code in IE8 looks like this:
The dd-tags are not inside the dt-tags like in firefox???
[attachment=0]code.png[/attachment]

On my phone (wp8 IE10) it looks the same.
Maybe a problem with my proxy at work? i will test it at home again.