I know it's a new motherboard an dnot much can be found around... but i installed my new parts last night :
MSI K9N AM2 mb,
AMD X2 3800+
2 x 512mb DDR2 800mhz gold edition,
250gb WD Sata2 16mb
PCI Sound Blaster Audigy
Quadro FX 1400 PCI-e
Pioneer burner the 111 (thei last burner)
and 1 IDE Maxtor 300gb 16mb HD

i have an other IDE HD on stand by... because there is only 1 IDE channel now... so i boot from CD to install Windows XP 32bits Pro with no IDE HD connected. installation goes fine and all.
I had downloaded on a USB key the latest drivers for the nforce550 platform from NVIDIA.com and then the Quadro drivers from NVIDIA.com and last, the drivers rfom CreativeLab for my Audigy 2 card.

Started having problems when i shutted down the PC, plugged in the 300gb IDE HD ( set to master , the dvd burner is in Slave mode ). trying to move ~100gb from the Maxtor 300gb IDE HD to my WD Sata2 drive... and in the middle of it, at some point, either the computer will reboot or freeze ...

Any idea or anyone aware of an IDE problem with this board/bios/ or nforce550 drivers ?

thx

Nvidia had issues with their nforce4 IDE drivers. It may have carried over to the NF5 drivers. Try deleting the Nvidia IDE drivers and use the Microsoft IDE drivers on the XP CD.

ok,i uninstalled the IDE drivers, same thing happens.
I tho it was maybe a fan thing, was reading that when the computer slows down the fan, some systems crash/reboot.. so i disabled all monitoring tools in the bios.

same thing happens.... now im wondering, could it be that my Antec 400Watts SmartPower 2.0 PSU can't handle that much?

because im planning to add also a few USB devices ( mic, game pad, webcam and USB keys... )

could it be that my systems runs out of power at some point and simply reboots cuz of no power?
anyway to figure out the power in use/required?

Last update. after fooling around a bit.
thinking i twas maybe power related.. i unplugged my dvd burner to save some power... same problem.

Here's my fix. IDE HD settings, the SMART was set to AUTO... after changing it to Enable. everything is running smooth.
no more crashing, random reboot out of nowhere...

was copying 50+gb of data ( from my IDE HD to my Sata2 HD )while listening to some mp3s and testing out Lineage 2 on my new machine... flawless.

to me, this sounds very stupid.. but i guess it's a bios related problem.
i think my board got version 1.2 going and i saw 1.3 available on MSI website.

so my case is close, just sharing my experience. have fun all