You might want to read this article on Vista Color Mgmt by Steve Upton. Click here.
Are you running Vista SP1? Perhaps some of the concerns are addressed in SP1.
I have been testing both Vista 32 and 64 bit, both with and without sp1. I received the OS's at no cost via a MS feedback program.
Built a new pc based on Intel Core2 Duo 3 ghz, 8 gb ram, etc etc to run Vista.
I was worried a bit before loading up Vista about the color management thing. If I remember right, MS and Canon collaborated on it.
I was able to get a good monitor (Samsung 215TW) profile using the i1 Display2/Match3 or whatever X-rite calls it these days.
The problem, bug, "feature" that kept popping up was a shift in screen colors away from the profile results. Light greys in some cases turned light pink. Very aggravating. This happened in both 32 and 64 bit versions, with and without sp1.
Poked around the web in the usual and not so usual places, and the only suggestions that appeared to work involved the nvidia display card. I killed the startup stuff nvidia put in, and it helped a little, but the shift was coming back eventually. Always.
I am now running Vista 64 sp1 and the only problem so far has been the color shift thing. In almost a desperation mode, I decided to disable the Windows firewall. I then did another monitor calibration, the "advanced" method where I set screen brightness and contrast manually and the result was excellent when checked against grayscale and color test images around the web. The color shift has not occurred since killing the firewall.
For now I am a happy camper with prints that match the screen close enough for this amateur. I am not a graphics pro with resources to try different devices, but I will poke around to find out what and how the Windows firewall interfered.
btw, barring any more color issues, Vista 64 has been very stable and performing well beyond my expectations. Photoshop CS3 and Lightroom are very fast on this Vista 64 system.