To reproduce:
1. Add a RadRibbonBar
2. Apply Office2013Light theme
3. Use the following code snippet:

public Form1()
{
    InitializeComponent();

    this.radRibbonBar1.CloseButton = false;
    this.radRibbonBar1.MinimizeButton = false;
    this.radRibbonBar1.MaximizeButton = false;
    this.radRibbonBar1.ApplicationMenuStyle = Telerik.WinControls.UI.ApplicationMenuStyle.ApplicationMenu;
}


Workaround:
this.radRibbonBar1.RibbonBarElement.ApplicationButtonElement.Margin = new Padding(3, 8, 0, 0);