Thank you for the provided information. It looks like there is a problem with the way that RadEditor for MOSS handles the default MOSS editor Auto Correct functionality. Normally if properties such as AllowTextMarkup, AllowFonts, AllowTables etc. are set in the SharePoint designer (For example:<PublishingWebControls:RichHtmlField id="Content" FieldName="PublishingPageContent" AllowFonts="false" runat="server"/>) and there is a problem with the content, RadEditor for MOSS pops up a confirmation dialog, which allows you to clean the content. In your case this feature of the control is not working properly.
I logged this in our bug-tracking system and I hope that we will be able to fix it for the next release, which is scheduled for the end of the next week.
You can follow the PITS Issue by its ID: 2630
All the best,
the Telerik team
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