If it does not (& I don't know the answer) , you do have options....I wanted to run the 64 bit version of XP Pro and my StarBand 360 only supports the 32 bit version of XP. So I run a dual boot on my computer, with XPx32 on one drive and XPx64 on the other drive.( I can do the same with Vista if I wanted a tri-boot) If you do not want to install a second hard drive, you can partition your hard drive and it will be treated as two separate hard drives.. Granted it isn't the easiest solution. However it has benefits. I can still run legacy apps under XPx32 which will not run under XPx64. I think you will find a lot of apps and hardware which ran great under XP will not work with Vista.. So dual booting might have some other benefits for you..
Vista, no matter what sales people and MS tells you is not all joy by any means..