Been waiting 18 months for this to be fixed. The RadTabStrib is completely unresponsive in Firefox because of this problem. When you click on the different tabs, the corresponding content page are not displayed. After switching to Telerik and converting our entire form application to use your controls, this problem appeared in the very next Telerik release, breaking all of our work in one of the most important browsers there is. This was not a good introduction to Telerik and even worse when nothing has been done 18 months later.