If you need to use virtual machines on Linux, try Virt-Manager. Virt-Manager is more reliable than VirtualBox. Virt-Manager is completely free and open-source. I'm a long-time supporter of VirtualBox.
Is the above possible? I'm using Ubuntu 11.10 with the current version of KVM, Qemu etc that is in their repo's. I have been trying to get this to work on a Windows XP guest for a day or so now, but ...