Balsa install

[Ross Schulman <ross brandeis edu>]

I'm trying to install Balsa-0.4.5 onto my Redhat 5.1 system, but when
./configure checks for GTK-version>=1.1.1, it dies.  I know I installed
GTK 1.1.2 from the RPMS on the GNOME ftp site.  This is from config.log:

configure:1949: checking for GTK - version >= 1.1.1
configure:2048: gcc -o conftest -g -O2 -I/usr/X11R6/include
-I/usr/lib/glib/include   conftest.c  -L/usr/lib -L/usr/X11R6/lib -lgtk
-lgdk -rdynamic -lgmodule -lglib -ldl -lXi -lXext -lX11 -lm 1>&5
In file included from /usr/include/gdk/gdk.h:23,
                 from /usr/include/gtk/gtk.h:23,
                 from configure:1974:
/usr/include/gdk/gdktypes.h:25: glib.h: No such file or directory
In file included from /usr/include/gtk/gtkarg.h:23,
                 from /usr/include/gtk/gtkobject.h:23,
                 from /usr/include/gtk/gtkaccelgroup.h:27,
                 from /usr/include/gtk/gtk.h:24,
                 from configure:1974:
/usr/include/gtk/gtktypeutils.h:23: glib.h: No such file or directory

Thanks to anyone who can help,
Ross Schulman