I am a Vista user w/ a Poken that works perfectly :)
You do not need a driver to use the Poken. When you put it in your USB, it should just autoload your browser (in this case, probably IE), and launch Start_Poken.html. That will take you to the DoYouPoken.com website.
If it doesn't launch automatically like in your case, just browse your computer, and go to the "Connect to Poken Website ". Open that drive, and double click "Start_Poken."
In the meanwhile I have figured out, that my Vista had been screwed up and had a general driver problem. After solving this issue my poken works perfectly.