Yum dependency issues for xorg-x11-tools

I'm trying to install xorg-x11-tools (on GNU/Linux 2.6.9-55.ELsmp REDHAT
Enterprise 4 i686), but am having dependency issues that I don't
understand.

"yum install xorg-x11-tools" stops with the following errors:
Error: Missing Dependency: xorg-x11-libs = 6.8.2-1.EL.13.37.2 is needed by
package xorg-x11
Error: Missing Dependency: xorg-x11-libs = 6.8.2-1.EL.13.37.2 is needed by
package xorg-x11-xfs

However I seem to already have higher versions of xorg-x11-libs than is
needed, as "yum list installed" says:
xorg-x11-devel.i386                      6.8.2-1.EL.33.0.2      installed
xorg-x11-libs.i386                       6.8.2-1.EL.33.0.2      installed

Also "yum install xorg-x11-libs" and "yum install xorg-x11-devel" both
finish with "Nothing to do".

What might be the problem here? Am I making some mistake?

Also, my /etc/yum.conf has the "baseurl" commented out for both [base] and
[updates]. Where else might the respository be set, and how can I find out
what repositories yum is using? Thanks.