Unfortunately I'm not quite sure what's the problem because I wasn't able to reproduce it. When I inherit our RadButton everything seems to be working fine. Could you please examine the attached sample project and see if is of any help to you.
If need further assistance please feel free to ask, but I'd like to ask you if you could send us some code snippets or a project that reproduces the issue.
All the best,
the Telerik team
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