Most likely, you simply have an error in your AOLserver config file.
Look at all the parts where you try to configure the database pools,
and compare to a known-good config file.
Or you're starting AOLserver in such a way that it can't find your
PostgreSQL libraries, as you imply above. How are you
starting AOLserver? Have you verified that it is in fact seeing the
environment variables above. I assume that the "D_LIBRARY_PATH" typo
occurs only in your post above, not in your actual code.
Why are you using such ancient versions of AOLserver and PostgreSQL?