To reproduce: Add a RadRibbonBar, add a ribbon tab with some groups and buttons. Run the application, autohide the content of the tabs, minimize the application, maximize it, open the tab the buttons are overlapping each other.
For me this happened on the second tab expansion from a minimized tab state. So the steps were: 1. Create a RadRibbonForm with RadRibbonBar and the Windows 7 theme. 2. Add several tabs. 3. Put several tab groups with 2 or more horizontally placed buttons