Retrieving OSes on usd HDD to MacBook

Before my computer had its Brazilian mishap in early May, I was able to boot to 5 other OSes (all Linux; Mepis, Fedora 8, Sabayon, PCLOS and Linux Mint).
Well, they're all back now. At least things are more or less set up for them to boot. However, still can't get Fedora to boot so I'll have to try a little harder there.
PCLOS also gave some problems. So while i had the root setting at /dev/sdb3 in the kernel boot line. in fact PCLOS sees this as /dev/sda3.
So, to get PCLOS to boot I had to change not only this in the Ubuntu /boot/grub/menu.lst but also all the sdb stuff in the PCLOS /etc/fstab had to be changed to sda.