VirtualBox in full screen on second monitor

I've been having real problems with this, and it turns out that the solution is really simple!

When you try to run a guest OS full screen, goes to the first monitor, so the menu bars etc. for Ubuntu are hidden.  To make it full screen on the second monitor:

1. Enter full screen with the guest OS
2. Hover over the VirtualBox hidden menu at the bottom of the guest OS
3. Click View | Virtual Screen 1 | Use Host Screen 2

This will make the guest OS show up in the second monitor when using full screen mode.  Works with Ubuntu 10.04 host and Windows 7 guest.