long story short, I installed Ubuntu 12.04 today on my Mac Book Pro, previously it has been dual booting Mac OSX and Windows 7 via the bootcamp. Since I have installed ubuntu i can no longer access the other two OS'. Specifically when I select Mac from the Grub2 menu, the screen just goes black and nothing happens. If i select windows7 from the menu it says invalid OS.
I only have one harddrive that is partitioned amongst the OS'. Gparted shows
/dev/sda1, Fat 32, /mnt/boot-sav/sda1, EFI, flag boot
/dev/sda2, hfs+, /mnt/boot-sav/sda2, Macintosh HD, flag boot
/dev/sda3, hfs+, /mnt/boot-sav/sda3, Recovery HD
/dev/sda4, ntfs, /mnt/boot-sav/sda4, Bootcamp
/dev/sda8, ext4, /
/dev/sda6, ext4, /mnt/boot-sav/sda6, Ubuntu
Additionally i know all the files for the other OS' are still there as i can see them in file manager. Also i cannot boot from CD, it flashes the traditionally white mac screen on start up for approx 1 second before going to the grub 2 bootloader.
any help would be much appreciated