psql error on postgresql-9.0 : psql: symbol lookup error: psql: undefined symbol: PQconnectdbParams

Hi,

I have installed postgresql-9.0 on my CentOS 6.0 server in the directory
/usr/pgsql-9.0/.
Its data directory resides in /var/lib/pgsql/9.0/

unable to run $psql dbname command

when i run the commands its showing the error like:

[root(at)CentOS-60-32-minimal ~]# su - postgres
-bash-4.1$ psql msdi
psql: symbol lookup error: psql: undefined symbol: PQconnectdbParams
-bash-4.1$

from two days working on it am not getting the soultion.
I searched around the internet got some suggestion like to run below command

[root(at)CentOS-60-32-minimal ~]# DYLD_LIBRARY_PATH=/usr/pgsql-9.0/lib psql
psql: symbol lookup error: psql: undefined symbol: PQconnectdbParams

once i run it, It showing the same error

so, please help me to come out from this problem...

--

Regards,*
*Suresh Hosur