or

Hi,
I use VS and Blend to build a wpf application. When using Blend all of a sudden I get the following error message
The name <telerik control tab/grid> does not exist in the namespace "http://schemas.telerik.com/2008/xaml/presentation"'
I have tried Clean, re-referencing, re-build but to no avail. This error is only in design time in Blend.
any advise?
P