I tried to create a sample page based on the provided description of your scenario but I was not able to reproduce the issue you mention neither in IE6/IE7, nor in FF.
Could you please open a support ticket and send us a simple running test project which demonstrates your exact setup and reproduces the problem? As soon as we receive it we will test it locally and research the issue. I would also like to ask you let us know what browser version you use. For your convenience I have attached a screenshot with instructions how to open a support ticket.
All the best,
the Telerik team
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