plpythonu on 7.4

On a 7.4 installation built --with-python...
Python installed is 2.3.4.

On createlang, I get the following error:

 createlang -U postgres 'plpythonu' template1
 createlang: language installation failed: ERROR:  could not load
 library "/usr/local/pgsql74/lib/plpython.so":
 /usr/local/pgsql74/lib/plpython.so: undefined symbol: PyDict_Copy

 Anyone have any hints?

 thanks,

 elein@varlena.com