Yolanda, I have the same issue. I need SPD to boot @ 400 fsb.
I'm planning buying an E8600 and I would love to run it @ 4 ghz but right now I'm unable to achieve rock solid stability with my old E6600 @ 400 fsb (using a lower multiplier)...

Could you please share with us what settings and voltages do you use?
(FSB Termination, ICH, etc. ?)

Thanks!