When I start Guide 9 (latest test update) the toolbar is correctly shown, at the right of the menubar.

Then I press shift+F11 to enter fullscreen and press it again to go back to window mode.

After doing that the toolbar is missing. Although if I hover the mouse over the place it was, the buttons are still there and react, but are invisible, simply the icon of each one is missing.

If I enter "Settings -> Toolbar..." and press OK without any changes buttons are shown again.

I'm running Guide over Windows 7 64bits.