I was looking at the specs on your motherboard, and I'm not seeing 400mhz FSB listed, I see 800hmz as the lowest. What processor are you running in it?

There's some confusion, because various busses are double- or even quad-pumped. The memory is generally double-pumped, but ratings are given at multiplied speed -- 667 MHz bus double-pumped means it's "1333 MHz" memory.
Meanwhile, FSB is generally quad-pumped, but specified at the general rate. Thus, a 333 MHz FSB is running at 1333 MHz effective; a 400 MHz FSB is running at a 1600 MHz effective rate.

I think there are three possible sources of confusion.

First, we don't know whether the BIOS is showing double-pumped or quad-pumped frequencies. My guess is that it's showing 400 Mhz, meaning 800 MHz (which means you need to set it up to 667 go get to 1333). However, it may be already overclocking your CPU to 1600, and showing 400, which means you'd need to lower it to 333.
If there is a 667 option on the FSB, chances are that it's showing the double-pumped value, and it ought to be at 667.

It's quite often the case that early motherboard BIOS-es don't detect memory or CPUs correctly, and end up defaulting to lower frequencies. Thus, you have to check your motherboard BIOS for updates. It may be that the motherboard will do a better job of detection after upgrading. If you're already have the highest available BIOS, and it still shows 400, then check what kind of CPU it's detecting. It may be that you don't have the CPU you think you have, perhaps?

Finally, when it comes to RAM, a bunch of manufacturers will put somewhat marginal chips "rated" for x MHz into a DIMM, but because they are marginal, they will put a SPD PROM on the DIMM that actually detects the memory at a lower rate. For example, you may think you got 1066 MHz RAM, but SPD declares it at 800 MHz. For people who don't check, this will run just fine, and very stable, and the performance loss is only visible if you go looking for it. To actually get to the rated speed, you often have to override the auto-detect in the BIOS. And, given that the chips are marginal (may only work with certain chipsets, on certain motherboards, or whatnot) you may or may not get it to work. If not, that's what the (8 weeks without memory, you pay shipping) lifetime warranty is for. Less than 1% of customers actually make use of that warranty, as far as I know.

Is the whole PC hardware industry shoddy? Pretty much, yes. If you take the time to test all the corner cases, and figure out what's needed to make the system run stable (chipset + CPU + RAM + graphics + drivers + Windows + whatnot) you will ship a year after everyone else, and cost twice as much, and thus you'll go out of business in a hurry. Someone else will ship something shoddier than you, much sooner, much cheaper, and let the customers sort it out. Because, let's face it, we all buy on price and checklist features, and not much else.