Please excuse us for the delayed response.
Can you please give us an example of the control that is currently not working on the Sitefinity page, so we can give you a more specific advice.
Please note that a Sitefinity page's lifecycle differs a bit from the standard .NET page lifecycle, thus we have developed the out of the box SitefinityUpdatePanel control, to accommodate users' needs to easily implement partial page updates. The only case this would not work is if you are trying to use it withing the context of a control inheriting from our SimpleView class, where the standard .NET UpdatePanel is recommended instead.
Please do not hesitate to let us know if any issues persist.
the Telerik team
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