I have checked the ASUS website for details on your motherboard. Certainly, it should be capable of running Vista 64-bit. Unfortunately, there is a snag. Going to the drivers download page and selecting Vista 64-bit as the operating system I have found that many of the drivers are Beta versions. These drivers are still in development, and may not work as expected. Certainly, this could explain your experience with Vista 64-bit. If motherboard drivers don't work as expected, there is little or no chance of any other devices working with your setup. Unfortunately, Vista 32-bit doesn't fare any better. As it stands, I cannot recommend that you use Vista on this machine, sorry. Keep checking the website, though. The following link is to the ASUS website page for your motherboard.
Dwarf
ASUSTeK Computer Inc.-Support-