Yes, your board will handle DDR400/PC3200 ram. You should have 3 ram slots, and it will hold a maximum of 2 gb of ram, however you should run ddr ram in pairs to gt the full effect (speed) of the ram (DDR runs faster in equal pairs, so if I were you I'd get 2 sticks of 1 gb ddr400/pc3200 ram).
That can be verified HERE
Now, as far as the manual stating that you need to have pc3200 ram in order for it to recognize a cpu with a fsb of 800mhz....that's kind of odd to me. I don't see why it would make a difference one way or the other. I have a 500mhz fsb cpu, and I'm running pc3200 ram with no issues at all. However, you might want to get a second opinion on that
From what I can find on google, your board is discontinued, so it's support might be limited. Try to find a direct link to the website for support for your board in your manual, and see what you come up with.
Hope it helps!
War produces veterans, wounded both physically and mentally. They have sacrificed for us.....and it is now our job to help these veterans, as they have already helped us in ways we will never know, in ways that we cannot fathom, and in ways that we take granted every day.