pgsql - failed

Hello!

After two days of unsuccessful attempt to compile pgadmin3 on SuSE 8.1 
I  realized I need some assistance.
On my system I have installed pkgconfig0.14.0, glib-2.2.3, pango-1.2.5, 
atk-1.2.4, gtk+-2.2.4 and wxWindows-pgAdmin3-20030831.
I have been running PostgreSQL 7.3.4  for days, using perl DBD-Pg 1.21. 
The database is located in standard directory /usr/local/pgsql.
When I start configure for pgadmin3 I get the following errror:
- checking pgsql in /usr/local/pgsql ... failed
- you must specify a valid pgsql installation with --with-pgsql=DIR

I must say that checking for libpq-fe.h returns YES.
But checking for PQexec in -lpq is not successful.
The output of rpm -qa | grep postgres is empty string!
The day before my frustration with this installation I managed to 
install the whole bunch of software on
Mandrake 9.1 (I know there are binary packages).

I would really appreciate any suggestion.  I am wondering where I  made  
a mistake.

Thanks                  Zvone Zagar