Just comparing it to my grub.conf, I have root=LABEL=/ here, since your
problems are coming from the initial root device I wonder if you should
try to relabel "Cata" as "/" and adjust grub.conf accordingly, in case
it has a special meaning... doesn't sound likely but it is a difference
in the right area for the symptom.
Also it might be work recooking your initrd now you changed the
/etc/fstab. Something like this should do
mkinitrd /boot/initrd-2.6.21-1.3194.fc7 2.6.21-1.3194.fc7
maybe you tried it already since you mentioned initrd contents in the
thread.
Otherwise as the others said you seem to have a lot of powers at your
disposal and to have used them... it's probably something dumb ;-)