i installed ubuntu karmic on aluminim macbook (pro) 5.1
its dualboot with windows and works wit refit and grub-pc.
installs without problem but wouldnt boot. I found a fix,
But i am not a guru so the steps i toke may be double or not realy needed.
I just tell what i did.

In short copied my /boot into my efi partition an created a grub.efi.

Got it from :
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=538730

I used super grub to boot when i wasnt able
http://www.supergrubdisk.org/
-> burn iso on cd-rom, startup while pressing c until i hear your cdplayer roar.



- install osx and refit. if this is done
- boot your karmic live cd/dvd and create your partions in gparted.
* i left 150mb between all partitions *
- install ubuntu and boot with super grub disk.
- install all updates and make wifi an videocard working.
- reboot with supergrub disk and then the tricky part.

1) mount EFI partition

# mount /dev/sda1 /efi

2) copy all kernels and such

# cp -a /boot /mnt/boot-fresh

3) create a grub dir

# mkdir /mnt/efi/grub

4) head to /mnt/boot-fresh

# cd /mnt/boot-fresh

5) make grub image

# ./grub-mkimage -d . -o grub.efi part_gpt hfsplus fat ext2 normal sh chain boot configfile

6) copy all data to /mnt/efi/grub

# cp grub.efi *.mod *.lst *.cfg /mnt/efi/grub
OR
# cp -A /mnt/boot/grub /mnt/efi/

7) make realy sure you have the needed files

# cd /usr/lib/grub/x86_64-efi ; cp *.mod fs.lst command.lst /mnt/efi/grub

8 ) Copy the grub.efi in the root folder of your efi partition

# cp /mnt/efi/grub/grub.efi /mnt/grub.efi

9) and then finaly update-grub2

# update-grub2

10)

# sudo reboot

it worked now


Blessings from Evan sorry for my english. if you encounter better ways to do it ill edit.