I ask that in the future you post only one thread for a given question as this makes it easier to answer it and harder to miss relevant information among several posts.
I have just replied to your other thread and I am pasting my reply here as well:
DataCaching should only be enabled for static content, controls should not be used inside, nor should elements with IDs that will duplicate. This feature keeps the HTML that has once been received from the server and does not request it again. This means that the instance on the server may no longer match the on on the client. This is explained in the data caching demo
If you need the content to be disposed you should disable caching. This will make the RadToolTipManager move the UpdatePanel that loads the content in the DOM to be inside the currently shown tooltip and thus only one instance of the server content will reside on the page.
the Telerik team
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