Compiling MapServer with PostGIS Support - Error

[Adam]

I'm compiling MapServer with PostGIS support.  PostGIS is installed and I
can load shapefiles and query them fine.

Now I'm trying to recomplie MapServer with PostGIS support and I'm getting
this error after compiliation:
[root at localhost mapserver-4.6.2]# ./mapserv -v
./mapserv: error while loading shared libraries: libpq.so.4: cannot open
shared object file: No such file or directory
[root at localhost mapserver-4.6.2]#

libpq.so.4 is located in two places:
/usr/local/pgsql/lib/libpq.so.4
/usr/local/src/pgsql/postgresql-8.1.1/src/interfaces/libpq/libpq.so.4

And for the ./configure line where I specify the PostgreSQL install I use:
--with-postgis=/usr/local/pgsql/bin/pg_config

pg_config is indeed in this directory.

I also ran "ldconfig".

Any ideas as to why I'm getting this error?