GRUB 10.04 MacBook /dev/sd3 (NEED HELP!!)

[Matt3223]

Thank you all this worked!
My situation was that I had the ol' grub on the MBR problem, but it didn't ruin everything... I could still boot OSX, however, ubuntu would not get past the grub menu upon booting with option held.

but, I had ubuntu installed and could boot to it on /dev/sda3 using superGrubDisk... so

I went to terminal in lucid and:

sudo grub-install --force /dev/sda3
sudo update-grub

after telling me how installing to a partition was a BAD idea... I shrugged and updated grub.

then booted back into OSX and followed wford002's link to rewrite the MBR on disk0.

rEFIt still would not boot linux on sda3 by selecting tux icon, but rebooting and holding down option and selecting "windows" booted me into ubuntu on sda3.

now to copy efi folder to desktop and then delete it off Macintosh HD so I don't have to mess with it anymore... for now.

[vibe3]

So it looks like Neddy's instructions seem to work for a lot of people, but those instructions are based on a "new" install off a CD? Has anyone successfully used the update manager to upgrade from 9.10 to 10.04 and avoid the grub problem?