I have had the same problem with windows 7 64bit the way round it was to set hot sync manager to sync via infared and also set the tungsten to sync via "IR to a PC/Handheld" then get a infared dongle to plug in via a usb port (unless your pc already has an infared port) and align the ports together and touch the hotsync button on the handheld screen manually
Its a bit slow like this but does solve the problem
Chris