I have posted this question on the apple forums too but if anyone has any suggestions of potential fixes - please let me know!
I have followed these steps in order to dual boot my MacBook (OS X Yosemite 10.10.5, 2.9GHz Intel i7) with Linux Ubuntu 14.04:
When the process of burning the Ubuntu 14.04 version (both 32-bit and 64-bit) has completed I get the following error message:
"The disk you inserted was not readable by this computer."
If I then boot from this disk all that appears on the screen is a blinking cursor. I have burned the disk using Disk Utilities at slowest speed of 2x and other speeds too. I've tried burning both 32-bit and 64-bit versions and used a 32-bit disk that I successfully dual-booted a windows system with the same unsuccessful outcome.
I have burned both 32-bit and 64-bit versions using Disk Utilities and Toast Titanium but I am still experiencing the same error.
Prior to booting from the Ubuntu disk I also partitioned my hard-drive to make room for Ubuntu.
Please help on this issue as I really need to get Ubuntu running on this system.
MacBook Pro (13-inch Mid 2012), OS X Yosemite (10.10.5)