I Use custom Skins and disable all Skins using the web.config. The problem is that RadTabStrip and Radwindows do not render properly. Please see images. If I change <add key="Telerik.EnableEmbeddedBaseStylesheet" value="false" /> to <add key="Telerik.EnableEmbeddedBaseStylesheet" value="true" /> everything start working. I use SharePoint 2010 as host and IE8. IE has limited of css files (31 css) and I try to use custom skins to minimize the css files so if I disable the base stylesheet I will be fine. So I will have only my custom skins which are 3 css.
Tha RadTabstrip show the list of tabs as regular ul and li. and the radwindows show all the images around the box.
Web.Config
<!-- Disables the embedded scripts and skins for all RadControls -->
<add key="Telerik.EnableEmbeddedSkins" value="false" />
<add key="Telerik.EnableEmbeddedBaseStylesheet" value="false" />
<add key="Telerik.EnableEmbeddedScripts" value="true" />
Tha RadTabstrip show the list of tabs as regular ul and li. and the radwindows show all the images around the box.
Web.Config
<!-- Disables the embedded scripts and skins for all RadControls -->
<add key="Telerik.EnableEmbeddedSkins" value="false" />
<add key="Telerik.EnableEmbeddedBaseStylesheet" value="false" />
<add key="Telerik.EnableEmbeddedScripts" value="true" />