I am afraid we are not able to determine the exact cause of the issue by the provided information so far. Do you face this problem with any of our demos?
Please provide us the exact steps to reproduce the issue or prepare and send us a very basic sample application demonstrating the erratic behavior. Thus, we will be able to further analyze the problem and provide a proper solution.
Meanwhile, you can try to temporarily disable any ajaxification ( RadAjaxManager, UpdatePanel or RadAjaxPanels, etc.) and enable your script debugging ( FireBug for instance ) to see whether there are any script errors interfering.
Looking forward to your reply.
the Telerik team
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