Set sdb to Master!
Then first in the boot order and if it were me, I would seriously consider re-installing suse.
Double check that grub is going to MBR on sdb
This pic shows it (though it has sda not sdb)
http://files.myopera.com/carl4926/albums/671478/19.png
Double check back here again at the summary that is shows sdb MBR and hasn't reverted back to something else, if it does there is something wrong in bios settings
http://files.myopera.com/carl4926/albums/671478/16.png