I have to fc distros installed on different partitions on my PC along with mdk and a few others. I decided to upgrade my video card and mdk and the others re-booted and allowed me to swap the card and then worked. Not Fedora. When I put the cd in to upgrade the system It goes through a few menus and tells me I have more than one device assigned / (the root partition) and tells me to re-boot (and repeat till I drop dead I suppose). I even tried moving one of the FC distros /etc/fstab file still the same complaint. Whe I boot linux rescue theres only one /. I have already tried copying the xorg config file from the mdk distro with now joy. Apart from manually running each boot script in recue mode does anyone have any ideas. I dont want to upgrade and even if I did it wont let me !.

After I put the card in I installed ubuntu (a debian based distro) and it re-installed grub, identifying all my distros (inc XP). maybe this messed it up ?.

There's a chance what's causing the problem is the way your fstab is written. There are two ways of identifying partitions: by their location and by their label. If you have 2 fc distros and they both use the labeling system, they may get confused as to which partition they're supposed to use. Imageine bith distros have identified their '/' partition with a '/root' label. On boot the system wouldn't know which to choose.

I would go into a working linux distro, or use a live-cd and change the fstab labels for locations (e.g. /dev/hda3)