Unable to install redhat 6.4 using kickstart on x3690 server

Hi,

I am trying to install redhat linux server 6.4 on x3690 X5 server. When i insert the rhel 6.4 iso I get the gnu grub menu, I don't get the option to hit the tab key to get to the boot prompt where I can insert my kickstart command.
The grub menu comes up with 3 options

1. red hat enterprise linux 6.4
2. install system with basic video driver
3. rescue

"use the up arrow and down arrow keys to select which entry is highlighted. Press enter to boot the selected OS, 'e' to edit the commands before booting, 'a' to modify the kernel arguments before booting, or 'c' for command-line"

At this point when I press the 'tab' key I don't get the boot option where I can put my kickstart http details.
When I press the 'e' key I get further 2 options:

kernel /images/pxeboot/vmlinuz
initrd /images/pxeboot/initrd.img

I change the initrd to initrd /images/pxeboot/initrdtest and then boot, the server then boots from the DVD. Which then allows me to do a fresh install of Linux. I don't get the option to put my http kickstart details.

Any ideas?

Ketan