I'm having some problems switching to different tty text consoles and back to gnome-shell with F16 as a guest in VirtualBox. I don't know how to go about figuring how if this is an F16 or Virtualbox anomaly or bug.
When I switch to tty3 or 4 text console, within a few seconds the VM window containing that text console has its contents replaced with part of the GUI tty. So looking at the screen shots attached, "normal.jpg" is what I see at first, and quickly changes to "anomalous.jpg" which seems to be part of the gnome-shell login window.
Yet the VirtualBox main application's Preview section shows the screen correctly - i.e. I can type commands and they will appear in the Preview section as expected but obviously way too small to read, while the VM window itself is obscured by this GUI overlay anomaly. See "preview.jpg"
If I use the Virtualbox menu to change to full screen or scale mode and then back, I can temporarily regain the text console, but it's always quickly replaced by this GUI anomaly.