Unfortunately, my friend and I ran into the same kind of wall when we were doing a dry ice run last weekend. The motherboard wouldn't boot over 343FSB, when the BIOS, manual, and website all said that it can natively support 400FSB CPUs. So, instead of getting 5GHz+ like we were hoping for, we only made it to 4.2
I'm using some $20 rosewill cooler with a copper core, I hear it's equalivent to Intel's stock cooler that has a copper core, I bought it as I bought my cpu used on ebay as newegg no longer carried E8200s so I had to buy a cooler to go with it.
I can get the machine to post at 3.6GHz however loading windows always retarts the machine, this mobo says 1600mhz oc(400 actual) and going even 1mhz over that will cause the machine to not load windows, makes me wonder if perhaps it's a chipset limitation and the sata controller fails at fsb's