Which version of the RadControls are you using, and which browsers / operating systems? I am asking because we have made improvements in this respect and you shouldn't be experiencing such issues.
The improvements were released about a year ago as a part of a major RadRibbonBar overhauling. If you are using older version, then you should upgrade.
If you are using a newer version, say 2012 Q2, and you are still having the same issue, then you should open a new support thread. Do include all relevant information that will help to produce the problem locally e.g. browser version, OS version, version of the controls, as well as a sample page that always exhibit this behaviour.
the Telerik team
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