This morning I was really surprised to find this thread
in Telerik forums. Here is the most interesting part:
"...found following thread: http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2670124&SiteID=1
If you scroll to the bottom of the thread you will read about a bizarre
situation in which if you have a Microsoft Wireless keyboard and you
unplug it then all your grayed out Telerik controls will start working!
Thank you very much Gavin for posting this!!! Absolutely unbelievable...