Hello Brete,
Indeed the disabled state of the Web20 skin does not stand out clearly. Please try adding this CSS in your page which will emphasize that the tab is disabled:
<style type="text/css">
.RadTabStrip_WebBlue .rtsDisabled .rtsIn
{
text-decoration: line-through !important;
color: gray !important;
cursor: default;
}
</style>
Regards,
Albert
the Telerik team