I am afraid that the provided information is not enough to determine the cause of the described problem. Please provide a more detailed information about your setup. For example, which are the other controls that are used, except RadGrid? How is the loading of the grid implemented?
Note that a full project is not needed. If you are able to isolate the problem in just a simple, fully runnable sample, it will be very useful because I will be able to examine the problem and inspect it locally.
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