Interestingly enough - I took the plunge and installed 5540 on my Macbook Pro and without a restart I tried to start my XP Pro VM - to my surprise it started up like normal under 5160! So I next shut the VM down, went into the config for the VM and change the setting to mount the XP drive image on the MacOS X desktop and tried to restart the VM. BANG - I was at the spinning ball of death!!!!!! So after a force quite and a restart - the VM now starts like before the the XP Drive image shows up on the MacOS desktop. So.... I think Alens comments are right on - either a service needs to be stopped and restarted or a forced system reboot needs to be implemented within the installer script!