Problems compiling the GTK+ 2.0 suite

[Edward Tripp <eltripp comcast net>]

I got version 2.6.4 of GTK+ and the required libraries--glib 2.6.4,
pango 1.8.1, and atk 1.9.0 and installed them in order until atk. ATK
configure cannot find the glib version I installed:
 
checking for GLIB - version >= 2.5.7...
*** 'pkg-config --modversion glib-2.0' returned 2.6.4, but GLIB (2.2.1)
*** was found! If pkg-config was correct, then it is best
*** to remove the old version of GLib. You may also be able to fix the
error
*** by modifying your LD_LIBRARY_PATH enviroment variable, or by editing
*** /etc/ld.so.conf. Make sure you have run ldconfig if that is
*** required on your system.

I followed all the hints, i.e. I set
PKG_CONFIG_PATH=/usr/local/lib/pkgconfig, the directory where the
glib-2.0.pc file is located, set the LD_LIBRARY_PATH to the same, edited
the /etc/ld.so.conf file, ran ldconfig.

Same error.
I do not know how to remove the old version; using rpm -e doesn't work
because so much software depends on it.

Any ideas?