install Mint instead of Ubuntu on Macbook Pro 3.1

[alicebtoklas]

Hi forum,
I'm trying to install Mint 13 on my Macbook Pro 15'' 3.1 for a dual boot Mint / Mac OS. Mint should actually replace Ubuntu which is already installed and working OK in dual boot with Mac OS using rEFIT and GRUB. The internal DVD player is dead so I'm working with an external (Sony) DVD player connected by USB. What happens when I boot with the Mint DVD in the player is the following:
- first (after a very long time, which is unusual) I get the rEFIT interface with the usual options ("Boot legacy OS from HD" - which is Ubuntu - and "Boot Mac OS from HD") and a new one which is "Boot Linux from CD"
- If I choose "Boot Linux from CD" I get a grey screen with the penguin for another very long time
- then I get the GRUB interface (same as usual) where I can only choose between Ubuntu, previous Linux versions, memtest and Mac OS. No mention of Mint. So I don't know what to do.

I've been reading a lot about dual boot and installing Mint on Macbook but I found nothing about installing Mint over Ubuntu (on an old MBP, what is more).

I would appreciate any help very, very much. Thanks!

[alicebtoklas]

bump!

[alicebtoklas]

To put it more simply I think GRUB doesn't detect the OS of the DVD or I need to tell GRUB to load the DVD instead of the usual OS. Someone has an idea?

Thanks

Alice