otrs3: skin design leads to inconsistent look

[subo]

Hi!

Version: OTRS 3.0.9 for openSUSE 11.x RPM
Following the skin design guide I've made various modifications to get our corporate design colors.

During this I noticed that if I add my modifications for Agent - Core.Default.css
line 76
a {
color: #F92;
text-decoration: none;
}
I get double headlinmes at the admin overview page for every topic. Strange to see that these headlines are formated with the <h4> tag.
line 107
h4 {
color: #333;
margin-bottom: 5px;
font-weight: bold;
}

Additionally the richt text edititor at "Tickets- New Phone Ticket" (and New Email Ticket) disappears. (Shows up but disappears immediately)
This happens only in Internet Explorer (9) but not in FireFox.

Does anyone have an idea why this happens or how to avoid it?
Thanx in advance,
-Subo