LOADing functions

Hi - I seem to be unable to reLOAD a shared library within the session that I LOADed it.  I am developing a UDF and my debugging changes do not appear to take until I quit psql and restart.  The following code sequence demonstrates the issue

kbmod=#  CREATE OR REPLACE FUNCTION hello(TEXT) RETURNS TEXT    AS '/Users/acbecker/src/github/kbmod/src/hello.so', 'hello'    LANGUAGE C STRICT;

kbmod=# SELECT hello( name ) FROM test;    hello      
----------------Hello4, XavierHello4, YariHello4, Zack
(3 rows)


### HERE I MODIFY hello.c TO TYPE "Hello5" AND REBUILD hello.so


### DROPPING AND RECREATING THE FUNCTION DOES NOT WORK

kbmod=# DROP FUNCTION hello(TEXT);

kbmod=#  CREATE OR REPLACE FUNCTION hello(TEXT) RETURNS TEXT    AS '/Users/acbecker/src/github/kbmod/src/hello.so', 'hello'    LANGUAGE C STRICT;

kbmod=# SELECT hello( name ) FROM test;   hello     
---------------Hello4, XavierHello4, YariHello4, Zack


### RELOADING THE SHARED LIBRARY ALSO DOES NOT HELP
kbmod=# LOAD '/Users/acbecker/src/github/kbmod/src/hello.so';
LOAD

kbmod=# SELECT hello( name ) FROM test;    hello      
----------------Hello4, XavierHello4, YariHello4, Zack
(3 rows)

### HOWEVER, AFTER QUITTING AND RESTARTING, THE CHANGE TAKES

kbmod=# \q

prompt>:/opt/local/lib/postgresql93/bin/psql -U postgres -d kbmod

psql (9.3.5)
Type "help" for help.

kbmod=# SELECT hello( name ) FROM test;    hello      
----------------Hello5, XavierHello5, YariHello5, Zack
(3 rows)

Hints as to what is going wrong here?  I would certainly expect to be able to re-load a shared library while debugging my UDF.

Thanks,
Andy

psql 9.3.5 from Macports
on OS X 10.10