basically turns out because its a Mac, using EFI boot scheme, grub wasnt being set up...thats my reckoning on things anyway
to solve this just popped in an Ubuntu Live cd and installed grub manually
here is the link i got it from
How to install Grub from a live Ubuntu cd. - Ubuntu Forums
but just in case it breaks here are the steps:
1. Boot up Live CD
2. type in a terminal window
sudo apt-get install grub
3. enter the following at the prompt you are given, follow closely!
root (hd0, 2)
this should return you to your bash prompt.
where 2 is the partition number returned by the find command.
SORRY for wasting anybodies time on the forum.