Unfortunately the provided information doesn't help us much in reproducing the issue. Can you please at least provide a live URL where the problem could be observed. In addition, please upgrade to the latest version of the control and let us know how it goes.
Furthermore, if the problem persists, I think it will be best if you can open a support ticket and send us a simple running project (incl. your custom skin, CSS, images, DB backup if needed and so on) demonstrating the problem (and step-by-step instructions on doing so). In that way we can reproduce and pinpoint the problems you're facing on our side, understand the logic of your application and provide a solution.
the Telerik team