To reproduce:

1. Collapse the ribbon
2. Select the tab to show the popup
3. Type some text in the RadDropDownListElement
4. Press Escape, Enter, Backspace keys. You will notice that these keys are not handled by the drop down. However, the ribbon popup is closed and there is no way to handle these keys.

Use the attached project to reproduce.

Workaround:
private void RadForm1_SizeChanged(object sender, EventArgs e)
{
    if (this.WindowState == FormWindowState.Normal)
    {
        this.SizeChanged -= RadForm1_SizeChanged;
        this.Size = new Size(this.Size.Width + 1, this.Size.Height + 1);
        this.Size = new Size(this.Size.Width - 1, this.Size.Height - 1);

        this.SizeChanged += RadForm1_SizeChanged;
    }
}

If I left-click on one of tab header, the related tab expand itself showing all the contained items.
But, if I expand the tab using the mouse right button, the tab expand itself but it appears blank!

Workaround:

private void radRibbonBar1_MouseDown(object sender, MouseEventArgs e)
{
    RibbonTab tab = this.radRibbonBar1.ElementTree.GetElementAtPoint(e.Location) as RibbonTab;
    if (tab!=null && e.Button== System.Windows.Forms.MouseButtons.Right)
    {
        tab.IsSelected = true;
    }
}

When Windows aero effects are enabled and the form width is being decreased, the title bar text appears over the title bar buttons and further more when continuing reducing the width of the form the buttons disappear and a small black rectangle is shown instead.

To reproduce:
- Set the Windows theme to Windows 7 Basic
- Start a RadRibbonForm and maximize it

Workaround:

void Form1_Resize(object sender, System.EventArgs e)
{
    if (this.WindowState == FormWindowState.Maximized)
    {
        this.RibbonBar.RibbonBarElement.IconPrimitive.Padding = new Padding(5, 5, 0, 0);
    }
    else
    {
        this.RibbonBar.RibbonBarElement.IconPrimitive.Padding = Padding.Empty;
    }
}