createlang on Mac OS X

I installed the PostgreSQL tools for Mac from the sourceforge site
(8.1.5). The server and client tools installed fine and the server is
running and accessible. However, it doesn't appear that the language
libraries got installed, as I can't install plpgsql. I get:

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

Unfortunately the bug reporting system on the postgresqlformac site
isn't working. Has anyone here gotten the langauge libraries to install
for use by this package? Is there a way to build and install just those
files? I like the convenience of the binary installer from the
postgresqlformac folks - are there other projects that have a binary
installer for Mac - I really don't want to recompile everytime an
update comes out.

Thanks