virtualbox.org

I'm using Ubuntu 10.04 and I want to virtualize Mac 10.6.3, but when I try to start the machine, a message that was not properly initialized the VT-x/AMD-V: But this option is enabled.
Full error message:
Hardware acceleration VT-x/AMD-V was enabled but not operational. Some guest systems (like OS / 2 and QNX) require this feature to work.
Make sure you have enabled features VT-x/AMD-V correctly in the BIOS of the host computer.

If I continue, nothing happens, it is black screen.

Processor? Checked in Bios? Bios Update available?

The Bios is update.
My processor is Athlon 64 X2 7750.
In the bios did not see this option.

The BIOS Option may have another name like "enable VT". For example search for "Secure Virtual Machine" or something like that.

If there is no option, your bios cant VT. And then you cannot use in VBOX.

Important notice regarding Mac OS X as Guest
Unsupported and not discussable here.