Your error message looks like the Adobe repository is causing you trouble. Perhaps try again with
su -c 'yum --disablerepo=adobe-linux-i386 install gcc'
If that still fails, try running
su -c 'yum clean all'
(seems to be a nearly reflexive first fix when yum misbehaves!) then the install command.
If all that fails, too, you could try manually installing the libgcc and gcc rpms. You can navigate to these rpm files from http://download.fedora.redhat.com/pu...inux/releases/
(start by choosing the relevant version of Fedora, then "Everything"). Having downloaded them both to your disk, you can install with
su -c 'rpm -ivh <libgcc-filename.rpm> <gcc-filename.rpm>'
The pain with this manual approach is "dependency hell": it is possible that you will need other rpms installed first. I've had a quick look and I think
you should have the other dependencies installed anyway, but sorry if I'm wrong.