Here is what I suggest you to do:
1. Execute an iisreset command on the SharePoint server.
2. After uninstalling RadEditor for MOSS solution, check if there are any RadEditor related files in the c:\Program Files\Common Files\Microsoft Shared\web server extensions\wpresources. If there are delete them.
If this does not help, Install the latest free
trial version of RadEditor for SharePoint 2010 (6.2.1). Disable all the features, which start with Use RadEditor ...
. Uninstall the solution http://www.telerik.com/help/aspnet-ajax/moss-sp2010-uninstalling-editor.html
. Check the mentioned above folder for RadEditorSharePoint releated files (delete them if there are any). Do an iisreset.
All the best,
the Telerik team
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