Hi!
It worked for me( First from daneleff). WindowsXP on hda, couple of fat partition on hdb, and fedora core 4 on the rest of the hdb. While installing, grub install option was selected to other boot partition (not MBR):
"Glorioso, try this;
Boot the Fedora cd disk #1 (installation disk).
At the installation menu, type in linux rescue (hit the enter key)
Once the system loads, at the terminal prompt, Type in chroot /mnt/sysimage
then;
grub-install --recheck/dev/hda
This may take a minute or so and should just return a command prompt with no errors. Once it does, type in reboot and see if grub comes up normally."
Thx daneloff!!