Hey,

1. I've installed on Ubuntu precise (12.04) using the deb package 7.0-20130311-002114-1 .
2. Visited the web interface and bam!

I get this error:

OpenERP Server Error

Client Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.7/openerp/addons/web/http.py", line 203, in dispatch
    response["result"] = method(self, **self.params)
  File "/usr/lib/pymodules/python2.7/openerp/addons/web/controllers/main.py", line 704, in get_list
    return db_list(req)
  File "/usr/lib/pymodules/python2.7/openerp/addons/web/controllers/main.py", line 88, in db_list
    dbs = proxy.list()
  File "/usr/lib/pymodules/python2.7/openerp/addons/web/session.py", line 31, in proxy_method
    result = self.session.send(self.service_name, method, *args)
  File "/usr/lib/pymodules/python2.7/openerp/addons/web/session.py", line 104, in send
    raise xmlrpclib.Fault(openerp.tools.ustr(e), formatted_info)


Server Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.7/openerp/addons/web/session.py", line 90, in send
    return openerp.netsvc.dispatch_rpc(service_name, method, args)
  File "/usr/lib/pymodules/python2.7/openerp/netsvc.py", line 293, in dispatch_rpc
    result = ExportService.getService(service_name).dispatch(method, params)
  File "/usr/lib/pymodules/python2.7/openerp/service/web_services.py", line 122, in dispatch
    return fn(*params)
  File "/usr/lib/pymodules/python2.7/openerp/service/web_services.py", line 351, in exp_list
    cr = db.cursor()
  File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 484, in cursor
    return Cursor(self._pool, self.dbname, serialized=serialized)
  File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 182, in __init__
    self._cnx = pool.borrow(dsn(dbname))
  File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 377, in _locked
    return fun(self, *args, **kwargs)
  File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 440, in borrow
    result = psycopg2.connect(dsn=dsn, connection_factory=PsycoConnection)
  File "/usr/lib/python2.7/dist-packages/psycopg2/__init__.py", line 179, in connect
    connection_factory=connection_factory, async=async)
OperationalError: FATAL:  role "openerp" does not exist

Edit: I went #dpkg-reconfigure openerp And I don't get this message anymore. Perhaps while the openerp package was configured initially, postgresql wasn't yet configured?