Linux was running fine on my system until the BIOS upgrade. Then it would get to the:
BIOS DATA CHECK OK, BOOING KERNEL
(reboot)
I wiped the HD after the bad stuff started going on
I think all that happened is that the HD geometry changed. THen the pointer to the active partition was NG. Going into the BIOS setup and redoing that and some other changes would have fixed it. Now you have to reinstall.
Were you the one that originally put the 2 OP SYtms on?
If you look from Windows, does the HD have the same size?