Formatting OSX partition I have a Macbook Pro with 3 partitions:


HFS (OSX)
FAT (Ubuntu)
NTFS (Windows 7)


and I want to format only the OSX partition and do a clean install without touching the other operating system partitions.
In order to do this I also have to format the MBR partition or erase it? I have rEFIt, and I know it has a utility that checks/repair the MBR or so I think so, should I use it after I do the clean install?
You should be able to repair the MBR after reinstalling OS X.
I would attempt to do a backup of all of your drives first in any way you prefer, so that if something /does/ go wrong (shouldn't), you have a backup.
I believe you can also repair the MBR from the Windows recovery partition.