Vista has an sp2 but that is not the solution to your problem. Vista does not use active sync. It uses the windows mobile device center:
http://www.microsoft.com/windowsmobi...-download.mspx
Start with your connection. You should be able to "see" a device on your pc. If you can then its the software. Try removing the windows mobile device center on pc and then reloading it. After reloading it then start it up. Once you have it started, then plug in the usb with ur phone. Wait to see what happens.
Its a pain to get the two to communicate initially so you are not alone in this problem. I know there is a thread here on this subject. Search my postings and you may find it.
You can also try hooking up to another machine to see if the pc is the problem. I use vista and xp and vista was a real pain to get to finally work out the kinks. Hang in there it will work.