Do you mean Preview mode of RadEditor or enabled="false" mode of RadEditor. When the editor is placed in Preview mode its scripts are loaded because it is still possible to switches the modes and modify the content. When the editor is placed in content preview only (Enabled="false") mode, its contents are rendered in a standard DIV element and the editor's scripts are not loaded on the page.
My suggestion is to download and try the latest version of Telerik.Web.UI, which we will release later today. If the problem still persists, isolate it in a simple working project and send it for examination via a support ticket.
the Telerik team
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