Here's something that it would be helpful if people with this board tried:
1. Set a CPU ratio of 6.0 (requires the latest BIOS with unlocked multiplier).
2. Set a memory divider of 1:1 (i.e DDR2-533 if your FSB is at 266 MHz).
3. Choose an FSB setting in the 360 to 400 MHz range. Hopefully this will leave your CPU and RAM near (or even below) their rated speeds.
4. Boot to windows, open SuperPi (or prime95, or whatever you're preferred stress-testing app is), and run the '8M' (or higher) benchmark, and report back whether or not is is stable.
...I'm asking about this because there appears to be a glitch that is preventing the board from reaching high FSB speeds, even when the CPU and RAM are not being overclocked, so I want to see if it's a common problem, and where it typically starts to kick in (I've heard reports of as low as 310 MHz and as high as 380 MHz...on my board it's about 350 MHz).
Basically, if I set my CPU multiplier to 6.0, and my RAM to 1:1, and my FSB to 360 MHz, the system is not at all stable, and increasing the FSB just causes it to become increasingly unstable. Note that the settings described would clock my CPU at 2.16 GHz and my RAM at DDR2-720. My CPU is rated for 2.4 GHz (E6600 Conroe) and my RAM is rated for DDR2-800, so these settings should not be a problem. Using higher multipliers coupled with lower FSB settings, I have verified that my CPU is stable to (at least) 3.0 GHz at stock voltages, and my RAM is stable to DDR2-1000, so like I said, there's no reason why the settings above should have been unstable, unless the board is just unable to cope wit hthe higher FSB settings for some reason.