Hello folks! I have a similar problem with this board and the Athlon X2 3800+ (Manchester) CPU, when I tried the other day to install 2 DIMMs of 1GB DDR-400 Corsair VS1GB400C3 memory to my existing 2 modules of Kingston KVR400X64C3A/1G (both pairs have the same chip layout and 2.6Volt rating). My PC doesn't even power on with 4 DIMM. Any configuration of 1, 2 (in dual channel) or 3 modules is working (although the manual states that 3 modules configurations don't work, they do, albeit in DDR-333 speed). I've tried BIOS default settings and using different versions (F8, F9, F10d). After pressing the power button and nothing happens, I remove a module and the PC instantly turns on!