have you tried the Vista drivers?
Theres a thread on here that has them, But the main post with some good install instructions are at MoDaCo. (The process was designed for people wanting to flash a rom from within vista, But its been noted that this driver can fix sync issues as well)
Also, Make sure to un-install any WM devices from your device manager. (make sure to un-check that "hide phantom devices" option too.)
http://www.modaco.com/content/Window...ltimate-guide/