I installed openSUSE 11.2 Milestone 7 x86_64 on a partition and chose to install the boot loader in the root partition’s boot sector. My master boot record is set up with GRUB to chain load different partition boot sectors to boot into different OSes, each configured with its own GRUB configuration.
The problem is that the openSUSE installation seems to overwrite my MBR with a standard DOS boot record that tries to boot from the first bootable partition. On the next boot I just got a message telling me to insert a bootable media. In other words, the GRUB I had installed in the MBR was wiped out and my system ended up being unbootable as a result. I had to boot from a rescue CD and reinstall GRUB in my MBR.
IMHO the SUSE installation should leave the MBR alone unless the user tells it to install a boot loader in the MBR. The installer should not make assumptions about what’s in the MBR and whether it can be safely overwritten. If a user chooses to install the boot loader in a partition boot sector, assume the user knows what she’s doing and leave the MBR alone.
If I remember correctly, on one of OpenSuSE inst “screens” there is special field for marking, that you want to install “generic MBR” into HDD mbr area.
May be this field was erroneously “switched on” at your installation ?
You should not have had to use the rescue CD if the install worked right. As for openSUSE installer changing the boot record. This normal but bypass-able. In the summary stage goto boot options and there you can make a boot disk, define where to put the bootloader etc. If you don’t review and finalize settings in the summary section, Linux will make it next best guess. IMHO computers are terrible at guessing rotfl!