VM needs CPU of Macbook support "Long mode"

[windforce]

Hi,

I have the VirtualBox installed on my Macbook Pro(10.6.8 ), and I want to install a linux VM(require CPU support "long mode") on VirtualBox.
When I launched the new VM, it prompts that "Your CPU does not support long mode. Use a 32bit distribution."

After searching for this problem, I found that support of CPU virtualization is required for this VM. Then I checked on my Macbook and its CPU is i7 which supports virtualization. So I guess the problem is related to the OS or EFI version.

Does any know what's the problem of my Macbook?
How should I do to enable the support of CPU virtualization?

[Perryg]

http://support.apple.com/kb/HT3773

[windforce]

it works!
thank you Perry!