Mmmh... most references I find about denied access to 0x80000001 cpuid register are referring to virtualization.
That's strange, it should not interfere at all, but if you can maybe try to enable Virtualization/Secure Virtual Machine in your bios if you haven't it yet active.
I have SVM enabled in BIOS (use it for Virtualbox). But the commands I write are in the host system.
990fx chipset nbvoltage?
I use TurionPowerControl to slightly overclock my FX-8320 and get very good results. I got 3.8Ghz, at low voltage 1.29V which keeps my CPU temperature underload about 55oC, with open air room (no air-conditioner). I do scientific computations and this fits well with my need. My BIOS settings is not working reliably, and I find TPC much easier to work with than messing with my BIOS.
My problem is the North Bridge gets very hot. About 86-87oC underload. I'd like to undervolt it to reduce the temperature, but it seems TurionPowerControl doesn't support my 990FX (my mainboard is MSI 990FXA-GD65) yet. Are you going to add support for this chipset soon?