I think you better check what everyone has said since mid-December and knows about Phenom NB and it's limitations and needs of high volts including Sami, gOtVoltage. If anyone knows how to oc or about Phenom, I'm sure you know Sami will. Email AMD support and find out.
Sadly, I have to say your BIOS has a major bug that you guys need to work out. Your NB so far is showing only results of it being very near 1800MHz NB in all instances where only multiplier is used only.

You're on X64, your bandwidth should be far far higher at only 2200MHz on NB 1066 and no tweaks whatsoever. Your bandwidth is low for such clocks. Those results our systems can beat with near stock NB frankly, and we know how NB perf. scales with speed very clearly.

Also according to AMD/Sami, those NB speeds are impossible. Even 3GHz/2.8GHz above subzero is impossible. You need LN2 to get such high speeds and damn high volts for. It's like you hitting 6.2GHz on Core 2 on air. Fact is, you'll have to prove it with performance of 2.5GHz NB first. That's why NB was released unsync with the cores, it's hard to clock and causes instability quickly. Absolutely no way you'll even hit 2.8GHz on air with less than 1.55V with it, mark my word.

The only way you can very clearly test NB speed is bandwidth/32M etc. They show your NB speed very very clearly. Like I said you should be over 18k Sandra with only 3.5GHz NB even without linear scaling (it scales pretty much linear).

At this moment, you should try working out what speed you're at by comparing performance of known NB speeds because your BIOS is giving off wrong NB values - most software will then fault based on it. I'll tell you a test for NB: WinRAR

It scales very well with NB, no need for CPU speed, only NB speed with 800 or 1066 RAM stock can show the NB speed. You should top 2500KB/s with 2300MHz CPU, 1066 RAM and 2800MHz NB or your real clocks are lower.

Hope you guys figure and test this out better and iron out these bugs, major bugs at that.