I just installed virtualbox for the first time. I'm running Ubuntu Linux and absolutely needed a windows app, but couldn't get Wine to work with sound, so I resorted to virtualbox.
So far I love it, but I have one very annoying problem. Once the VM takes hold of my mouse I can't get it back. I'm a newbie to this program, so maybe I don't know what I'm doing, but I thought I should be able to hit the host key, which is the right-ctrl key by default, and then I could get my mouse back to the root/host linux GUI. This is not working, nothing seems to work except if I'm not in full-screen mode I can hit the PRINT SCREEN key to bring up a GNOME print screen utility that returns mouse control to my host OS, but this is annoying, and I would prefer to be able to use it in full-screen mode, but once I enter full screen I have to reboot to exit it.
My guess is that Ubuntu/Gnome are not working well with sharing the keyboard with VirtualBox and that this is a common problem for anyone trying to do this.
BTW: I'm on Ubuntu 8.04 x64 release with current updates.