libpython - cannot open shared object file

Hi,

I have got PostgreSQL 8.4 up and running on my Ubuntu Server 64-bit OS, but I am having difficulty with the PL/Python functions from my database. In particular, I am running this:

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drop language plpythonu cascade;
create language plpythonu;

-- Utility
CREATE OR REPLACE FUNCTION min_float(a float, b float) RETURNS float AS $$
return min(a,b);
$$ LANGUAGE plpythonu;

SELECT min_float(1,2);

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And receiving this error message:

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NOTICE:  drop cascades to function min_float(double precision,double precision)


ERROR:  could not load library "/opt/PostgreSQL/8.4/lib/postgresql/plpython.so": libpython2.3.so.1.0: cannot open shared object file: No such file or directory

********** Error **********

ERROR: could not load library "/opt/PostgreSQL/8.4/lib/postgresql/plpython.so": libpython2.3.so.1.0: cannot open shared object file: No such file or directory
SQL state: 58P01
-------------------------------------------------------

The strange thing is that I have successfully created plpythonu language and the PLPythonu function(s). I was originally having difficulty getting PL/Python to install and it was throwing a similar error. However, this everntually went away once I added the PostgreSQL root install dir to the PATH variable (in my .bashrc and .bash_profile). I have both Python26 and Python31 installed (both came with ubuntu I believe).

I am not sure that I have put my PATH and LD_LIBRARY_PATH settings into the correct .bash_profile and .bashrc files so that PgAdmin3 and psql (being opened by other users) will have the correct settings.

Any ideas/help much appreciated?

Thanks,
Tom