Installation problem (RH5, x86-64, Postgresql 8.4.4)

I can't install plpython:
bash-3.2$ createlang --echo plpythonu template1
SELECT oid FROM pg_catalog.pg_language WHERE lanname = 'plpythonu';
CREATE LANGUAGE "plpythonu";
createlang: language installation failed: ERROR: could not access file
"$libdir/plpython": No such file or directory

Everything is installed from the official pgdg84 repository:
-bash-3.2$ rpm -qa|grep postgres
compat-postgresql-libs-4-1PGDG.rhel5
postgresql-server-8.4.4-2PGDG.el5
postgresql-plperl-8.4.4-2PGDG.el5
postgresql-libs-8.4.4-2PGDG.el5
postgresql-python-3.8.1-7PGDG.rhel5
postgresql-jdbc-8.4.701-1PGDG.rhel5
postgresql-8.4.4-2PGDG.el5
postgresql-contrib-8.4.4-2PGDG.el5

The database tells me the following:

postgres=# select version();

version

--------------------------------------------------------------------------------
----------------------------------
PostgreSQL 8.4.4 on x86_64-redhat-linux-gnu, compiled by GCC gcc (GCC)
4.1.2 20
080704 (Red Hat 4.1.2-46), 64-bit
(1 row)
uname -a:
Linux lpo-postgres-01 2.6.18-194.el5 #1 SMP Tue Mar 16 21:52:39 EDT 2010
x86_64 x86_64 x86_64 GNU/Linux

-bash-3.2$ cat /etc/redhat-release
Red Hat Enterprise Linux Server release 5.5 (Tikanga)
-bash-3.2$

--

Mladen Gogala
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