is from RPMFORGE
and in the older 5 series rpmforge was and still is incompatible with centos5 base and update repo's
this is a VERY OLD and very well documented issue that was SO BIG of a problem
that was mostly fixed in Centos 6
you MUST !!!!!
must use ether "yum-priorities" plugin or yum-protectbase" plugin
AND CONFIGURE IT !!!!!!!
Did you read any of the WARNINGS
on the centos wiki about "third party repos ?
and the wiki page for the "Priorities" plugin
you must configure the plugin and the data base
AND remove any current incompatible RF rpm's
to get a list of "rf" rpms installed
rpm -qa | grep rf > /rpmforgelist.txt
then uninstall the rf rpm's
yum remove NameOfTheProgram
I didn't create my CentOS 5.3 system
as you know 5.3 is now 7 versions and 3+ years out of date
and 3+ years past it's end of life
i would take this opportunity to upgrade to the current ( and very last) older 5 series version