[CentOS] Problems with 4.3 install - didnt write boot record

the first time i tried to install centos on my fileserver it detected
my reiserfs drives but then didnt give me a kernel to actually access
them - strike one

now im trying centos on my mail server, wipe the drives, created a
mirrored raid array from the setup, (took over 14 hours to format and
sync) finally finished the install AND IT DIDNT WRITE THE BOOT RECORD!
when it rebooted i got my grub menu from GENTOO! - strike two,

now im back into the install cd, trying to figure out how to install
grub like the install should have done for me, but there is no grub
command at the prompt (trying to use tab completion) im ready to hurt
something im so frustrated, can anyone help me out here? ive seen
http://www.dur.ac.uk/a.d.stribblehill/mirrored_grub.html but without
the grub command that page is useless.  Im sure someone has to be
booting RH/CentOS off mirrored software raid, some help please! id
like to get this thing going tonight if possible, thanks!

Nick