Thanks, I did the what the second post on that link that you sent suggested (copied below) and it seems to have fixed the problem:
Just in case this helps someone from spending the hours I did looking around.. I have the issue where the Mint 14 live CD worked, install went OK but then on booting to HDD there was no grub menu and just a black screen and blinking cursor. Convinced it would be a graphics card thing I played around with editing grub with replacement to "no splash" but no joy.
Then I found an old post about mint 11 (I am trying to install mint 14) and xenopeek suggested boot-repair.
Original Post was http://forum.linuxmint.com/viewtopic.php?f=46&t=86258
And the solution that worked for me and got me into Mint 14 was to boot to a live CD, the run
sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair
I just accepted the defaults when running the utility, it seemed to know exactly where my HDD was and fixed the grub on that /dev/sda.