pltlc and pltlcu problems

I try this code

CREATE FUNCTION  pltclu_call_handler() RETURNS OPAQUE AS 
'/usr/lib/postgresql/pltcl.so' LANGUAGE 'C';

and get this error

ERROR:  Load of file /usr/lib/postgresql/pltcl.so failed: 
/usr/lib/postgresql/pltcl.so: undefined symbol: pg_get_enconv_by_encoding

anyone help me with this?

murray hobbs

ps here's my .configure command

./configure  --enable-multibyte=UNICODE --enable-unicode-conversion --enable-locale  --bindir=/usr/local/bin
--libdir=/usr/lib--includedir=/usr/include --mandir=/usr/local/man --with-tcl --enable-odbc --with-unixodbc
--enable-syslog