I believe that there is just one version of that actual Bootcamp 2 and it is Boot Camp 2.0 that came with your Leopard disk. It includes the Boot Camp 2.0 Windows Drivers. As far as I can tell there is no such thing as Boot Camp 2.1 ro 2.2. Unfortunately, you will find people mixing the terms for Boot Camp and Boot Camp Windows Drivers. There are two updates available for the Boot Camp 2.0 Windows Drivers. You can find them at
http://www.apple.com/downloads/macosx/apple/application_updates/bootcampwindowsx pdriversupdate21.html
and
http://www.apple.com/downloads/macosx/apple/application_updates/bootcampdriversu pdate22forwindows.html
The 2.1 Update actually can be used as a install directly onto BootCamp without the Apple Drivers. The 2.2 Update must have the 2.1 Update already installed.
Boot Camp 3.0 is only for OSX 10 Snow Leopard. At least, that's what I've been told on this discussion group. In any case, you can only get it on a Snow Leopard install disk.
I just went through **** and Back installing Boot Camp 2 on my Mac Book Pro. See the thread in this discussion group at
http://discussions.apple.com/thread.jspa?threadID=2292702&tstart=0
to give you some background on the problems that I was having and the entry I made yesterday to describe the workaround that I was able to find.
http://discussions.apple.com/thread.jspa?threadID=2299567&tstart=0
There are Video Adapter problems. Mine was with the Radeon X1600 driver. I don't know whether there are similar problems with other video drivers.
You have an additional problem that I didn't in that you have tried to install the Boot Camp 2.1 Driver Update onto a pre-existing Windows XP SP3. I can't help you with that directly, but I did see a very interesting website during my troubleshooting that I think may help you out at
http://www.macwindows.com/bootcamp.html
There is actually a tip there labeled
"Boot Camp 2.1 and Windows XP SP3
TIP: Fixing Win XP if you accidentally install SP3 before Boot Camp 2.1"
Good Luck. I hope you can solve your problems with less pain than I had to go through.
Dave