Are you trying to use the default MOSS Link Manager in FireFox browser? Be
cause you should know that it is only IE complaint. What I suggest you to do is configure the RadEditor for MOSS to use the LinkManager dialogue provided by Telerik. In order to do so you need to modify the respective ToolsFile.xml
(for forms scenarios such wiki, list, blog ...) which, are located in the /Program Files/Common Files/Microsoft Shared/web server extensions/wpresources/RadEditorSharePoint/18.104.22.168__1f131a624888eeed/RadControls/Editor/
For example add the following line.
|<tool name="LinkManager" />
I hope this helps.
All the best,
the Telerik team
, the state of the art learning tool for Telerik products.