I was having the same problem. I'm on RH Linux 6.0. After editing /etc/ld.so.conf, it was necessary to do /sbin/ldconfig (like it says in the handy
untar_dir/INSTALL file). Then I restarted AOLserver and everything was fine, but I had a further problem.
While trying to register I got a dml error. The log said:
[03/Apr/2000:11:01:52 -0400][2117.2120][-Scheduler-] Error: Ns_PgExec: result status: 7 message: ERROR: stat failed on file '/usr/lib/pgsql/plpgsql.so': No such file or directory
To fix it I did:
ln -s /usr/local/pgsql/lib /usr/lib/pgsql
Everything worked great after that. Hope this helps others!