Why would the addons_path not be being picked up from /etc/openerp/openerp.conf?

I have 3 different openerp servers that have been upgraded to the "Valentine's Day .deb" OpenERP version 7.0-20130214-002355

Two of them are behaving 'correctly' picking up addons_path = /opt/openerp/addons from the openerp.conf

2013-02-14 20:57:56,970 5044 INFO ? openerp: addons paths: /opt/openerp/addons

While another, with the same addons_path = /opt/openerp/addons is giving me ..

2013-02-14 21:15:14,682 18264 INFO ? openerp: addons paths: /usr/lib/pymodules/python2.7/openerp/addons

Is there anything that could be telling it to ignore the addons_path from the conf file?