I have the neo4-f
you WILL NOT reach 266fsb from bios with a Winchester. there is a 219mhz 'bug' that the bios for this board simply cannot get around. This applies only to 3000+/3200+ Winchesters week 0410 and later so check your Winnie for which week it is.
the highest FSB you will be able to post is 219 if you have a later Winnie.
You can get around this by running overclocking through ClockGen and running a startup script. I am doing this now as a workaround and am running my winnie at 305FSBx8 w/Corsair VS on a 140 divider @2.5,3,3,6 1T. In bios, again, cannot get past 219. Set up all your voltage, RAM, etc. in bios and use ClockGen from there. I even OC to 219x10 in bios just to boot faster and then use ClockGen to apply a 8x divider and 305 FSB upon Windows startup.
once you get the San Diego chip, this board will haul balls straight out of bios and your problems will be solved.
If I could make some suggestions:
1. modular PSUs are complete garbage, kitschy as they may be. buy the Powerstream instead of the modstream. MUCH better.
2. don't worry about RAM dividers. this board has :100/120/133/140/150/166/180/200. I think you can find a good FSB/RAM combo in there somewhere

.
3. forget the Epox, especially if you are getting a San Diego in the near future. the budget boards just don't have the overclocking features and option of the Neo4-F. I have a Chaintech VNF4Ultra as well, similar to the Epox, great overclocker doesn't have the dividers, voltage options, etc. (example-chipset voltage on VNF4Ultra goes to 1.7, the Msi goes to 1.85)
if you want some assistance using ClockGen to get around the FSB '219 bug' until you get your San Diego, please let me know. Works like a champ in the meantime
long story short: this is the best board I've ever owned and will get better when I get a 4400.
p.s. the 1.71-1.73 beta bioses appear to at least partially solve the Winnie '219 bug' although you lose the 120/140/180 dividers in the beta versions. I used the 1.71 for a bit and could reach 250FSB with a 3x multi.
'219 bug' details (Winchester week 0410and later). From what I've found in my own testing, this is directly related to HTT multi somehow:
v1.6 official bios:
219x(4x) HTT multi=no problem
229x(3x or 2x)=boot, (4x)=no post
239x(1x)=boot, (2x-4x)=no post
v1.71 beta bios:
219x(4x)=no problem
229x(4x)=no problem
239x(4x)=no problem
250x(4x)=no problem
251FSB=no post
MSI is getting closer to a fix

IF it makes you feel any better, I had the same exact issue with my VNF4Ultra, but it would not boot past 250FSB no matter what HTT multi.