SoYo have released a new bios for the SOYO P4X400 DRAGON Ultra and it's version 2AA1! Dated 2002-08-22.

one more thing of note is that SOYO Names Mushkin Enhanced Memory Systems The Recommended DDR400 Memory Partner For Its New P4X400 DRAGON Ultra Motherboard, and Launches New SOYO DRAGON/Mushkin DDR400 Joint Promotion Program

But if you check the Compatible list for the SOYO-P4X400 DRAGON Ultra, Here's what it Listed! DDR400 SDRAM is supported, but support is dependent on BIOS settings, hardware profile, and other factors, and is not guaranteed! So will it work? LOL Hit Read More For your Bios

Download SOYO-P4X400 DRAGON Ultra Bios v2AA1 This upgrade requires Awdflash.exe