On 2014/09 updated t1, t2, t1hilo to lastest centos 6.5 ( from centos 6.2), There are the
procedure I followed.
Need to remove openoffice as it had a conflict with the update yum could not resolve.
And centos 6.5 works OK with stock video driver, so nvidia 3rd party driver was removed.

1. Yum update

Remove openoffice due to conflict with update, then update

  yum remove openoffice.org-brand openoffice.org-calc openoffice.org-calc-core openoffice.org-core \
  openoffice.org-draw openoffice.org-draw-core openoffice.org-graphicfilter openoffice.org-impress \
  openoffice.org-impress-core openoffice.org-langpack-en openoffice.org-math openoffice.org-math-core \
  openoffice.org-opensymbol-fonts.noarch openoffice.org-pdfimport openoffice.org-presenter-screen  \
  openoffice.org-ure openoffice.org-writer openoffice.org-writer-core openoffice.org-xsltfilter

  yum update

  vi /etc/rc.local      // comment out pmac driver
  vi /etc/inittab       // set run mode to 3         
  reboot

Remove nvidia drive (will use stock video driver now - as desktop now spans the 2 monitors)

  cd /home/tcs3/public_html/tcs3/computers/linux/1205_nvidia
  sh NVIDIA-Linux-x86-295.40.run --uninstall
  delete the /etc/X11/xorg.conf files

  vi /etc/inittab       // set run mode to 5         
  reboot (X should be working)

2. Recompile/install new TCS to /home/to


Recomile & install new TCS binaries to /home/to.

  vi /etc/rc.local      // comment IN pmac driver
  reboot
  start the TCS