Funny, I spent a great deal of time researching this as well last night and saw tons of posts with various configurations indicating freezes either in BIOS or while running Vista.
You may try to phone Asus and see if they can ship you an upgrated BIOS chip. They're pretty easy to install, you need a chip puller (about $5.00). I had to do this with my old P4n Diamond board.
On another note, I saw a discussion primarily geared toward overclocking but you may gain some information from it as it is a similar configuration as yours.
http://www.bit-tech.net/hardware/200...2_quad_q6600/1