psql always looking in /tmp for socket

Hello List,

regarding my last post....

 >My problem with LD_LIBRARY_PATH set is still the same....
 >(unix_socket_directory is set to /var/run/postgresql in >postgresql.conf):

 >arwen:~# /usr/local/postgresql7.2.1/bin/psql -p 6543 template1
 >psql: could not connect to server: No such file or directory
 >        Is the server running locally and accepting
 >        connections on Unix domain socket "/tmp/.s.PGSQL.6543"?
 >arwen:~#

 >Why is psql looking in /tmp and not in /var/run/postgresql ? Can i set
 >this somewhere? Any hints??

i found that setting $PGHOST to /var/run/postgresql solves this problem.
Is this the sommon solution?

another question about the setting of LD_LIBRARY_PATH: where to best set
this variable? Now the debian installation and the source installation
both use the libs from the source installation (i set it in /etc/profile)?

Regards
Tina