proxmox 2.3 cannot boot from usb (created using dd in ubuntu)

I have installed hyper-V 2012 standalone in my desktop.
I then downloaded proxmox 2.3 iso file and follow the steps in http://pve.proxmox.com/wiki/Install_from_USB_Stick (using dd in ubuntu)
when I press F11 in my desktop during boot-up, I managed to get to boot option and select USB
then I can see there is blinking light on my USB, then it stays on black screen.
I try to boot it in my laptop, and the same problem happens.

I have checked the md5sum with the iso, no problem.

Thanks