I suspect all supergrub did was to put a stage 1 ...= mbr for grub back into mbr but it did not re-link to the balance of its booting files...which is why I do not recommend it.
If you have a good live cd....boot it and
Code:
su
grub
root (hd0,.....and press tab to see what your partitions are
.....c is normally hd0,0
....linux ones will be hd0,1 or 2 etc type 83
.....linux swap will be type 82
so pretending you have one huge c partion its
root (hd0,1)
setup (hd0)
quit
Last line must say succeeded otherwise you have pointed to wrong hd0,1 and it maybe hd0,2 hd0,3 etc