'Unable to start pgsql' when importing map into Nominatim

Hi, I have been trying to import a planet file into Nominatim using the command ./setup.php --osm-file us-northeast.osm.pbf --all. System is running PostgreSQL 9.1, PostGIS 2, Nominatim 2 on CentOs 6.3.

When I try to do the import, I get the following error:

Create DB
Setup DB
unable to start pgsql

I have disabled open_basedir protection via WHM. I have no problem connecting to the pgsql database nominatim as the superuser used to run the planet file import. Command used to do so is:

psql -p 5432 -d nominatim

Any ideas how this can be solved? Thank you!