Well, it's not the fstab that's youre problem. It's the initrd image that's failing. Of course, I don't know for what asinine reason RedHat/Fedora is using initrd, so I've got no way to help.

Some things online point to it not being able to load /boot (which is what the failed to mount ext3 thing is about). Did you compile or otherwise install a new kernel? If so, did it include ext3 support built-in (that is, not as a module)?