Thanks to all the detailed tips you've posted for the issue I managed to do import psycopg2 in the CentOS 5.8 VPS:
-Removed all pg installations in the system (luckily there were no dbs to backup)
-Built/Installed last PostgreSQL dist. at standard location under /usr/local
-Re-built/installed psycopg2 source dist. (set proper pg_config parameter in setup.cfg)
-I had to do this too, because psycopg2 still complained about libqp.so.5 location (maybe because of not setting lib dirs in setup.cfg):
# cp /usr/local/<pg lib> /usr/lib
After those steps Python2.7.3 plus psycopg2 runs ok. I think the last step might have something to do with the fact that the python interpreter libraries are installed under /opt/... which I think is a distribution non-standard location setup
Note: perhaps this needs further tests for db connection or other issues
Thank you very much