Attached is a screenshot of how the code affected the RadGroupBox when the style is set to
.radGroupBox1.GroupBoxStyle = RadGroupBoxStyle.Office;
This is for Q3 2010 SP1 (the latest version) Are you using an earlier version? If so, I would advise to upgrade as there are many enhancements, fixes and new products available in the latest version.
Please let me know if I can help further