diff --git a/trytond/osv/osv.py b/trytond/osv/osv.py
index a2c9eaaecd..6100e78975 100644
--- a/trytond/osv/osv.py
+++ b/trytond/osv/osv.py
@@ -46,9 +46,10 @@ class OSVService(Service):
             res = getattr(obj, method)(cursor, user, *args, **kargs)
             return res
         except Exception, exception:
-            if CONFIG['verbose'] or str(exception.args[0]) not in \
+            if CONFIG['verbose'] or (exception.args \
+                    and str(exception.args[0]) not in \
                     ('NotLogged', 'ConcurrencyException', 'UserError',
-                            'UserWarning'):
+                            'UserWarning')):
                 tb_s = reduce(lambda x, y: x+y,
                         traceback.format_exception(*sys.exc_info()))
                 logger = logging.getLogger("web-service")
diff --git a/trytond/report/report.py b/trytond/report/report.py
index 43541b80cb..7b88d72411 100644
--- a/trytond/report/report.py
+++ b/trytond/report/report.py
@@ -56,9 +56,10 @@ class ReportService(Service):
             res = report.execute(cursor, user, ids, datas, context)
             return res
         except Exception, exception:
-            if CONFIG['verbose'] or str(exception.args[0]) not in \
+            if CONFIG['verbose'] or (exception.args \
+                    and str(exception.args[0]) not in \
                     ('NotLogged', 'ConcurrencyException', 'UserError',
-                            'UserWarning'):
+                            'UserWarning')):
                 tb_s = reduce(lambda x, y: x+y,
                         traceback.format_exception(*sys.exc_info()))
                 logging.getLogger("web-service").error(
diff --git a/trytond/wizard/wizard.py b/trytond/wizard/wizard.py
index 6dee6205d7..83256b1933 100644
--- a/trytond/wizard/wizard.py
+++ b/trytond/wizard/wizard.py
@@ -34,9 +34,10 @@ class WizardService(Service):
             res = wizard.execute(cursor, user, data, state, context)
             return res
         except Exception, exception:
-            if CONFIG['verbose'] or str(exception.args[0]) not in \
+            if CONFIG['verbose'] or (exception.args \
+                    and str(exception.args[0]) not in \
                     ('NotLogged', 'ConcurrencyException', 'UserError',
-                            'UserWarning'):
+                            'UserWarning')):
                 tb_s = reduce(lambda x, y: x+y,
                         traceback.format_exception(*sys.exc_info()))
                 logging.getLogger("web-service").error(