Thank you for the additional information provided. We will have it in mind when working on the issue.
It also happens when any code is changed and the designer is reopened. I get four bogus messages relating to radLabel and RadButton controls. To reproduce the error maybe be more curious since I have only one form (my most complex one) which presents this designer bug. Other form windows in my app having both labels and buttons do not do this. The app builds and runs fine however so it does not prevent continued development and testing.