could not access file "$libdir/plpgsql": No such file or directory

Hello List,

Trying to install 9.1.3 according to the INSTALL directions:
./configure
gmake
su
gmake install
adduser postgres
mkdir /usr/local/pgsql/data
chown postgres /usr/local/pgsql/data
su - postgres
/usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data
/usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data >logfile 2>&1 &
/usr/local/pgsql/bin/createdb test
/usr/local/pgsql/bin/psql test

Everything goes perfectly until I try to do this:
initdb -D /usr/local/pgsql/data

I get this output and error:

The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.

The database cluster will be initialized with locale C.
The default database encoding has accordingly been set to SQL_ASCII.
The default text search configuration will be set to "english".

fixing permissions on existing directory /usr/local/pgsql/data ... ok
creating subdirectories ... ok
selecting default max_connections ... 100
selecting default shared_buffers ... 24MB
creating configuration files ... ok
creating template1 database in /usr/local/pgsql/data/base/1 ... ok
initializing pg_authid ... ok
initializing dependencies ... ok
creating system views ... ok
loading system objects' descriptions ... ok
creating collations ... ok
creating conversions ... ok
creating dictionaries ... ok
setting privileges on built-in objects ... ok
creating information schema ... ok
loading PL/pgSQL server-side language ... FATAL: could not access file "$libdir/plpgsql": No such file or directory
STATEMENT: CREATE EXTENSION plpgsql;

child process exited with exit code 1
initdb: removing contents of data directory "/usr/local/pgsql/data"

I don't know what this means nor how to fix it. In my $MY_PREFIX/lib directory I have these:
libecpg.a
libecpg_compat.a
libpgport.a
libpgtypes.a
libpq.a
pgxs

The pgxs is a directory itself.

My configuration line when building was:
./configure --prefix=$MY_PREFIX --disable-nls --disable-shared --disable-rpath --enable-thread-safety --without-tcl --without-perl
--without-python
--without-gssapi --without-krb5 --without-pam --without-ldap --without-bonjour --without-openssl --without-selinux
--without-ossp-uuid --without-libxml
--without-readline --with-zlib --with-includes=${ZLIB_DIR}/include --with-libraries=${ZLIB_DIR}/lib

The configure, compile and install went fine. BTW, I am trying to enable as little as possible because it will be used on an embeded
ARM9 device, but I will certainly enable whatever is necessary.

Any help would be appreciated.

Thanks,
Vic