XUbuntu 12.10 Change Desktop to Headless server / occasional xubuntu desktop machine

[Vontux]

It has been quite a while since I've posted on the Ubuntu forums, because it has been quite a while since I've used Ubuntu or Linux in general. I've recently returned from a couple of years in the dark world of Windows and have returned to the light of linux. Levity aside I have a problem that I'd like some help with if possible. I have a Xubuntu 12.10 32 bit Desktop computer. It is a pretty slow single core machine, but has a rather large hard drive attached. I have been using it mostly as an experimental machine and as a makeshift ssh file server. I recently had the monitor I was using with it die on me, as a result, it has become far less convenient for me to use the GUI. Unfortunately it does not boot properly when the monitor is not present. I do have periodic access to another monitor and have been using that to get it to boot, but it would be nice to be able to set it up as a headless server.
I will still need to retain the ability to use the desktop because on occasion this computer serves as an Open Office workstation or media machine when I have guests or bring it along when I am someone else's guest. How would I go about setting my current installation up, which is the standard XUbuntu desktop to be able to function as a headless server, without losing the ability to run the GUI when I need to use it as a traditional desktop? Thanks in advance for any help that can be provided.

[Vontux]

I did some googling, and stumbled onto this thread: http://ubuntuforums.org/showthread.php?t=1920378 which seems to indicate that Xubuntu desktop should be able to boot without a monitor, but can't do so without a keyboard unless otherwise configured. I seem to be able to boot without a keyboard or mouse, I just seem to run into trouble when I try to boot without the monitor.