You got bit by a bug in the glibc update. See
https://www.centos.org/modules/newbb...30939&forum=37.
Quickest solution is to open up a terminal (right-click on the desktop background should give you that option), become root, and run "yum downgrade glibc".
You can prevent the broken update from being accepted again by adding this line to your /etc/yum.conf :
Code:
exclude=glibc*-2.5-58.el5_6.2 nscd-2.5-58.el5_6.2