grub-install with 2 hard disks

[Imran Akbar]

Hi,
    I have two hard disks (a SATA on channel 1 master and a ide on 
channel 2 slave) - but when booting up linux after an install of linux 
to the mbr on the sata i can't boot into grub but just a cryptic line of 
code.  when i try booting from a rescue disk and doing a grub-install 
/dev/sda i either get a response saying i don't have permission to do 
so, or that there is no /dev/sda device (not that it's not mounted, that 
it doesn't exist!).

thanks
Imran