Hey everyone,

I just upgraded to OS X 10.7 on my dual boot macbook, and now my ubuntu partition won't boot. When I choose the Ubuntu partition, it loads grub recovery and won't go any further. OS X works fine.

I have been using rEFIt to choose which OS to boot into, but I have alos tried holding down the option key at startup to avoid it as well. I have run disk utility repair on the partition and I get the following message:

Invalid BS_jmpBoot in boot block: 000000

Does this mean that there is something seriously wrong with the partitioning of the disk, and I should start thinking about a clean install of everything?

General question: What puzzles me most is how upgrading to Lion on one partition would affect the ability to boot in another partition. My understanding is that the whole purpose of partitioning is to isolate parts of the disk so stuff like this wouldn't happen.

Thanks,
D