You need to chroot the environment before running grub cmds. as root do the following while running from a live linuxcoin session.
mkdir myhdd
mount /dev/sda1 myhdd
mount -o bind /proc myhdd/proc
mount -o bind /sys myhdd/sys
mount -o bind /dev myhdd/dev
chroot myhdd
Now you can purge and reinstall grub. I would do the above then follow the ubuntu fix up guide. I don't know where this bug comes from I've tested the installer numerous times and always had success ?
Yea, thanks for the reply, I give up, there are the cmds u give me then there are a crap load of cmds from the other, it will just lead me to no where as i been trying since my first post in this thread. nothing but waste of time and power running a second pc trying. I'll just stick with my debian 6.0.2.1 install. Trying to mix ubuntu cmds with & fixes with linuxcoin cmds and mixes of grub version, my head is spinning.
I will send you a donation soon after I get my second gfx for giving your time trying to help me.
Whoooo there boy !! Take a few deep breaths and go roll yourself a fatty

I feel your frustration as I've been in your position lots of times !! I'm going to list everything you need to do on your machine to fix following the ubuntu tutorial. Feel free to give it a go when you feel more like it
Assuming you have completed the installer and have the grub error
1) Boot from linuxcoin
2)
mkdir myhdd
mount /dev/sda1 myhdd
mount -o bind /proc myhdd/proc
mount -o bind /sys myhdd/sys
mount -o bind /dev myhdd/dev
chroot myhdd
export DEBIAN_FRONTEND=noninteractive
apt-get update
apt-get purge grub2
apt-get install grub2
for i in $(ls /usr/sbin | grep grub); do paxctl -C /usr/sbin/$i; paxctl -cEr /usr/sbin/$i; done
update-grub
grub-install /dev/sda
exit
init 6
3) Hopefully enjoy linuxcoin