I think there is a bug with the buttons mode of the Rotator. I was able to reproduce it and I think that it will not be a problem to resolve it and send you a custom hotfix build. If you want the custom build, just open a formal support ticket. If this is not a serious issue for your application, you can wait until the next service pack release, which will also include the fix.
All the best,
the Telerik team
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