First make sure that the editor is activated for the site where your wiki list is located. Open a wiki page and from that page open the site settings. Click the Site Features link and make sure that both RadEditor features are active.
If the features are active and you still see the original editor, then you need to verify that the physical list editor control exists. Check if the file \Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\CONTROLTEMPLATES\RadEditorList.ascx is present on the server. If it is not there, then you need to deactivate both editor features and activate them again. Restart IIS after that to enable the new control.
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