Question about memory settings on P5B Deluxe

[RandomUser]

My new system includes:

P5B Deluxe Wifi - 614 bios
2G(2*1G) Corsair XMS DDR2-800 Ram 4-4-4-12
Core2Duo E6400

At stock/auto settings, the memory is detected as PC-4300 (on the post screen).

I went into the bios and changed it to DDR2-800 and it shows as PC-6400 on boot.

However, when I up the FSB to 400, it shows again as PC-4300 again on the post screen.

And after increasing FSB to 400, my only options are 800/1000/1200/1400/1600.

Is the post screen simply misleading? Or is it really running at 533 instead of 800?

How can I test it?

 

[RandomUser]

After doing a bit more research, I downloaded CPU-Z and it is showing the memory running at PC-6400 settings (400MHZ 1:1 4/4/4/12 in the Memory Tab).

So I am assuming that it is running at the correct speeds and that the post message is an anomaly, but I'd be happier if I had some confirmation from someone who knows more than I do.