matplotlib Redhat 9.0 install problems

Hi, I'm new to using matplotlib and am having some problems installing the software package. Basically my setup is:
* Redhat 9.0
* gcc 3.3
* Python 2.4 (installed in a non-standard location)
* freetype 2.1.9 and numarray 1.2.2 also installed in a non-standard location.

Following the instructions on the matplotlib homepage, I:
1. Substitute:
  'linux2' : [
with:
  'linux2' : [os.environ['ACSROOT'], os.environ['PYTHON_ROOT']

within matplotlib-0.72.1/setupext.py. The ACSROOT environment variable is where numarray is installed and the numarray headers can be found in $ACSROOT/include/numarray/.
2. Set BUILD_AGG=1
3. Run the command 'python setup.py build' which gives output that looks correct until gcc is executed:
  running build_ext
  building 'matplotlib._na_transforms' extension
  creating build/temp.linux-i686-2.4
  creating build/temp.linux-i686-2.4/src
  creating build/temp.linux-i686-2.4/CXX
  gcc -fno-strict-aliasing -DNDEBUG -g -O3 -Wall -Wstrict-prototypes -pipe -D_POSIX_THREADS -D_POSIX_THREAD_SAFE_FUNCTIONS -D_REENTRANT -DACE_HAS_AIO_CALLS -fcheck-new -Wall -fPIC -g -DDEBUG -O -DCCS_LIGHT -fPIC -Isrc -I. -I/alma/ACS-4.0/Python/include/python2.4 -c src/_na_transforms.cpp -o build/temp.linux-i686-2.4/src/_na_transforms.o -DNUMARRAY=1
  In file included from /alma/ACS-4.0/Python/include/python2.4/Python.h:8,
                   from CXX/Objects.hxx:9,
                   from CXX/Extensions.hxx:18,
                   from src/_transforms.h:12,
                   from src/_na_transforms.cpp:2:
  /alma/ACS-4.0/Python/include/python2.4/pyconfig.h:835:1: warning: "_POSIX_C_SOURCE" redefined
  In file included from /alma/ACS-4.0/gnu/include/c++/3.3/i386-redhat-linux/bits/os_defines.h:39,
                   from /alma/ACS-4.0/gnu/include/c++/3.3/i386-redhat-linux/bits/c++config.h:35,
                   from /alma/ACS-4.0/gnu/include/c++/3.3/functional:53,
                   from src/_na_transforms.cpp:1:
  /usr/include/features.h:131:1: warning: this is the location of the previous definition
  src/_na_transforms.cpp:6:35: numarray/arrayobject.h: No such file or directory
  ...

Just looking at the output it appears as if the changes made to basedir (i.e., 'linux2') in setupext.py are not having any sort of effect (hence the error message about numarray/arrayobject.h not existing). Is there something blatantly wrong I'm doing? Any help would be greatly appreciated.

Thanks in advance,

David Fugate