Fedora 13 boot.iso not working with "askmethod"

[H.S.]

When I boot from a USB Fedora 13 boot disk (using boot.iso from Fedora 
13), I press TAB on the boot screen and append "askmethod" (without 
quotes) to the kernel options line and boot. But the screen ends up 
black and nothing happens.

If I do not give any options, the boot proceeds and goes through the 
questions and wants me to select a physical device with the installation 
image. Basically, no problems there.

If I use "asknetwork" option, the boot works and asks for network 
configuration.

So, what is the deal with "askmethod"? How do I tell the installer to do 
installation from the internet?

Thanks.