Thank you for reporting this problem!
We are working on the editor's dialog and the problem is due to that
the ascx files in the EditorDialogs folder used in the example are not
updated to their latest version. To fix the problem you should update
the dialog files in the EditorDialogs folder with these ones available
in the latest Q3 SP2 2008 installation.
Please, note that there will be new enhancements in the built-in
dialogs of RadEditor Q1 2008. For example the link manager will feature
a reference to the Document manager - see the attached screenshot. That
is why if you upgrade to the new version once it becomes available,
then you should also upgrade the EditorDialogs folder again.
the Telerik team