Sorry it was my mistake of not telling you exactly what to do.
Choice #1:
If you are able to boot up Mint manually using the Grub prompt, which you said you can in Post #14 then try these commands in a terminal
Code:
sudo su
grub-install /dev/sda
Choice #2 (if Choice #1 fails)
Boot up Mint Linux as Live CD and try these instructions
Code:
sudo su
mkdir /mnt/dude_said_mount_here
mount /dev/sdb6 /mnt/dude_said_mount_here
mount --bind /dev /mnt/dude_said_mount_here/dev
grub-install --root-directory=/mnt/dude_said_mount_here /dev/sda
You can do either but the first one is a lot faster. Try Choice #2 only if #1 fails. I missed out the red bit in my last post.
The two choices are essentially the same but in the 1st choice you boot up the resident Mint already and have no necessity to mount the partition or to tell Grub what is its root directory. The second choice work with any distro that has Grub2 inside.