diff --git a/openerp/osv/fields.py b/openerp/osv/fields.py
index 568a52f2bf4..4e8eedf718b 100644
--- a/openerp/osv/fields.py
+++ b/openerp/osv/fields.py
@@ -1067,6 +1067,8 @@ class function(_column):
             self._classic_write = True
             if type=='binary':
                 self._symbol_get=lambda x:x and str(x)
+            else:
+                self._prefetch = True
 
         if type == 'float':
             self._symbol_c = float._symbol_c
diff --git a/openerp/osv/orm.py b/openerp/osv/orm.py
index eb5f637622b..eefe013cc42 100644
--- a/openerp/osv/orm.py
+++ b/openerp/osv/orm.py
@@ -385,11 +385,11 @@ class browse_record(object):
             # if the field is a classic one or a many2one, we'll fetch all classic and many2one fields
             if col._prefetch:
                 # gen the list of "local" (ie not inherited) fields which are classic or many2one
-                fields_to_fetch = filter(lambda x: x[1]._classic_write, self._table._columns.items())
+                fields_to_fetch = filter(lambda x: x[1]._classic_write and x[1]._prefetch, self._table._columns.items())
                 # gen the list of inherited fields
                 inherits = map(lambda x: (x[0], x[1][2]), self._table._inherit_fields.items())
                 # complete the field list with the inherited fields which are classic or many2one
-                fields_to_fetch += filter(lambda x: x[1]._classic_write, inherits)
+                fields_to_fetch += filter(lambda x: x[1]._classic_write and x[1]._prefetch, inherits)
             # otherwise we fetch only that field
             else:
                 fields_to_fetch = [(name, col)]
@@ -1034,6 +1034,7 @@ class BaseModel(object):
                 'ondelete': field['on_delete'],
                 'translate': (field['translate']),
                 'manual': True,
+                '_prefetch': False,
                 #'select': int(field['select_level'])
             }
 
diff --git a/openerp/report/render/rml2pdf/utils.py b/openerp/report/render/rml2pdf/utils.py
index ae70cd46c94..6fce8106b49 100644
--- a/openerp/report/render/rml2pdf/utils.py
+++ b/openerp/report/render/rml2pdf/utils.py
@@ -116,10 +116,13 @@ def _process_text(self, txt):
             result += tools.ustr(self.localcontext.get('translate', lambda x:x)(to_translate))
             if sps:
                 txt = None
-                expr = sps.pop(0)
-                txt = eval(expr, self.localcontext)
-                if txt and isinstance(txt, basestring):
-                    txt = tools.ustr(txt)
+                try:
+                    expr = sps.pop(0)
+                    txt = eval(expr, self.localcontext)
+                    if txt and isinstance(txt, basestring):
+                        txt = tools.ustr(txt)
+                except Exception:
+                    _logger.error("Failed to evaluate expression [[ %s ]] with context %r while rendering report, ignored.", expr, self.localcontext)
                 if isinstance(txt, basestring):
                     result += txt
                 elif txt and (txt is not None) and (txt is not False):
diff --git a/openerp/service/workers.py b/openerp/service/workers.py
index 1075342919d..8fec2767471 100644
--- a/openerp/service/workers.py
+++ b/openerp/service/workers.py
@@ -196,7 +196,7 @@ class Multicorn(object):
 
     def stop(self, graceful=True):
         if self.long_polling_pid is not None:
-            self.worker_kill(self.long_polling_pid, signal.SIGTERM)
+            self.worker_kill(self.long_polling_pid, signal.SIGKILL)     # FIXME make longpolling process handle SIGTERM correctly
             self.long_polling_pid = None
         if graceful:
             _logger.info("Stopping gracefully")
@@ -392,14 +392,18 @@ class WorkerCron(Worker):
             interval = 60 + self.pid % 10 # chorus effect
             time.sleep(interval)
 
-    def process_work(self):
-        rpc_request = logging.getLogger('openerp.netsvc.rpc.request')
-        rpc_request_flag = rpc_request.isEnabledFor(logging.DEBUG)
-        _logger.debug("WorkerCron (%s) polling for jobs", self.pid)
+    def _db_list(self):
         if config['db_name']:
             db_names = config['db_name'].split(',')
         else:
             db_names = openerp.service.db.exp_list(True)
+        return db_names
+
+    def process_work(self):
+        rpc_request = logging.getLogger('openerp.netsvc.rpc.request')
+        rpc_request_flag = rpc_request.isEnabledFor(logging.DEBUG)
+        _logger.debug("WorkerCron (%s) polling for jobs", self.pid)
+        db_names = self._db_list()
         if len(db_names):
             self.db_index = (self.db_index + 1) % len(db_names)
             db_name = db_names[self.db_index]
@@ -433,8 +437,15 @@ class WorkerCron(Worker):
             self.db_index = 0
 
     def start(self):
+        os.nice(10)     # mommy always told me to be nice with others...
         Worker.start(self)
         self.multi.socket.close()
         openerp.service.start_internal()
 
+        # chorus effect: make cron workers do not all start at first database
+        mct = config['max_cron_threads']
+        p = float(self.pid % mct) / mct
+        self.db_index = int(len(self._db_list()) * p)
+
+
 # vim:expandtab:smartindent:tabstop=4:softtabstop=4:shiftwidth=4: