I ran into problems trying to attach my new Canon EOS 350D camera to my laptop running Windows XP x64 Edition. Naturally the problem is that there were no x64 drivers for the camera in the accompanying cd set (old 32-bit drivers won't work). I sent a question to Canon whether they exist or not through https://self-service.canon-europe.com, and got a reply yesterday saying that no such thing exists. Too bad, it is an excellent camera. Luckily I have computers at home with 32-bit Windows installed :)
I encourage everyone with the same problem to visit https://self-service.canon-europe.com and submit a request for x64 drivers, maybe someday something will show up at http://software.canon-europe.com/.