This is a very strange error and there seems to be no answers on the web for it. I found some cases on the CentOS forums and the recommendation was to reinstall the whole OS. This is how I solved it.

as superuser

#yum remove php-common

(this command may remove a lot of installed software, you must make a list and install them again)

#yum install php-gd

(this will install the proper version of php-common and php-gd)

1. Check if there is an internet connection

2. If internet connection is ok. edit /etc/yum.conf.

3. look for the proxy settings which would look something like “proxy=http://192.168.1.1:3128″

4. Check if this proxy is working.

5. Delete the whole line if you’re not using an internet proxy server

This took me around 2 weeks to complete.

Here are the proper (easy) steps on how to do it

1. Update your linux kernel, install the tools then restart your computer (root)

$yum install kernel-devel
$yum install gcc
$yum install gcc-c++
$yum install make
$yum update kernel

2. download the driver here

3. run the driver from the command line (as root)

$./ati-driver-installer-9-1-x86.x86_64.run

4. run aticonfig

$aticonfig –initial –force

5. check if driver is working

$fglrxinfo
OpenGL vendor string: ATI Technologies Inc.
OpenGL renderer string: Radeon X1550 Series
OpenGL version string: 2.1.8395 Release

$glxinfo | grep direct
direct rendering: Yes

If this did not work, check the install logs (/usr/share/ati/fglrx-install.log)

There are two ways of adding yum repositories to your centOS system

1. Drop .repo files into your /etc/yum.repos.d/ directory

2. Add a repository entry in your /etc/yum.conf file

you can go to http://osresources.com/11_6_en.html for more on this.