erro while loading shared libraries: can't open libpq.so.3

Hi All,
Took a break from developing on pgsql 7.3 to set up network printing
where I added another host(localhost 193.168.1.2) in red hat network
settings.  Later, when I started psql I got the following error when I
issue this command:

psql -h localhost -U postgres nba

postmaster successfully started
-bash-2.05b$ psql -h localhost -U postgres nba
psql: error while loading shared libraries: libpq.so.3: cannot open
shared object file: No such file or directory
-bash-2.05b$

Any ideas what could be causing the problem?
Thanks in advance,
Phil Campaigne