When ever i try to install GCC on my linux (centos) It comes back with missing
glibc-headers-2.5-58.el5_6.4.x86_64 from updates has depsolving problems --
Yes, you could edit the yum.conf file, or you could simply do this:
yum install kernel-headers --disableexcludes=all
Do note that even if your admin is trying to install an excluded package from your RHN Satellite server via the normal process, it will still fail due to the local configuration.
(This holds for RHEL6 / cent6 (centos6) as well, of course.)