xorg-x11 isn't in the updates directory. The following two packages are:
- xorg-x11-libs
- xorg-x11-Mesa-libGL
Which when you execute the following you see:
# rpm -e --test xorg-x11-libs xorg-x11-Mesa-libGL
error: Failed dependencies:
libICE.so.6 is needed by (installed) libungif-4.1.3-1.el4.2.i386
libICE.so.6 is needed by (installed) libungif-progs-4.1.3-1.el4.2.i386
libICE.so.6 is needed by (installed) gifsicle-1.48-1.el4.rf.i386
libSM.so.6 is needed by (installed) libungif-4.1.3-1.el4.2.i386
libSM.so.6 is needed by (installed) libungif-progs-4.1.3-1.el4.2.i386
libSM.so.6 is needed by (installed) gifsicle-1.48-1.el4.rf.i386
libX11.so.6 is needed by (installed) libungif-4.1.3-1.el4.2.i386
libX11.so.6 is needed by (installed) libungif-progs-4.1.3-1.el4.2.i386
libX11.so.6 is needed by (installed) gifsicle-1.48-1.el4.rf.i386
This tells you that these packages are required by gifsicle and linungif. Both of which are part of the OCR spamassassin plugin.