I think its enabled. Here is the file
Code:
# CentOS-Base.repo
#
# This file uses a new mirrorlist system developed by Lance Davis for CentOS.
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the #mirrorlist does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base
#mirrorlisthttp://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
baseurl=http://mirror.trouble-free.net/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
priority=1
#released updates
[updates]
name=CentOS-$releasever - Updates
#mirrorlisthttp://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
baseurl=http://mirror.trouble-free.net/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
priority=1
#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever - Addons
#mirrorlisthttp://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=addons
baseurl=http://mirror.trouble-free.net/centos/$releasever/addons/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
priority=1
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
#mirrorlisthttp://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
baseurl=http://mirror.trouble-free.net/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
priority=1
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
#mirrorlisthttp://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
baseurl=http://mirror.trouble-free.net/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
priority=2
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib
#mirrorlisthttp://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
baseurl=http://mirror.trouble-free.net/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
priority=2