It seems that your using the wrong path.

http://mirrors.nl.kernel.org/centos/5.3/os/i386/repodata/repomd.xml

Te good path is:

http://mirrors.nl.kernel.org/centos/5/os/i386/repodata/repomd.xml 

Here is also a message:

This directory (and version of CentOS) is depreciated.  For normal users,

you should use /5/ and not /5.3/ in your path. Please see this FAQ

concerning the CentOS release scheme:

http://www.centos.org/modules/smartfaq/faq.php?faqid=34

Greetz,

Michaël Jonkers

Van: centos-mirror-bounces@centos.org [mailto:centos-mirror-bounces@centos.org] Namens Chris Chiu
Verzonden: maandag 14 november 2011 8:49
Aan: centos-mirror@centos.org
Onderwerp: [CentOS-mirror] 5.3 mirrors issue

Do anyone having some issue ..

we are using 5.3 , and trying update and install some packet.....sounds like centos removed 5.3 ( i think ) ?

here is the error output

Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirrors.nl.kernel.org
 * updates: ftp.heanet.ie
 * addons: mirror.bytemark.co.uk
 * extras: mirror.bytemark.co.uk
http://mirrors.nl.kernel.org/centos/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://mirror.bytemark.co.uk/centos/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://ftp.heanet.ie/pub/centos/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://mirror.sov.uk.goscomb.net/centos/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://mirror.ukhost4u.com/centos/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 400: Bad Request
Trying other mirror.
http://www.mirrorservice.org/sites/mirror.centos.org/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 400: Bad Request
Trying other mirror.
http://mirrors.ukfast.co.uk/sites/ftp.centos.org/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 400: Bad Request
Trying other mirror.
http://mirrors.dedipower.com/centos/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 400: Bad Request
Trying other mirror.
http://anorien.csc.warwick.ac.uk/mirrors/centos/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://mirror.as29550.net/mirror.centos.org/5.3/os/i386/repodata/repomd.xml: [Errno 14] HTTP Error 400: Bad Request
Trying other mirror.
Error: Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again