diff --git a/addons/crm/crm_lead.py b/addons/crm/crm_lead.py
index 546431ac7c7..e00813af011 100644
--- a/addons/crm/crm_lead.py
+++ b/addons/crm/crm_lead.py
@@ -85,7 +85,7 @@ class crm_lead(osv.osv):
                             resource_id = resource_ids[0]
 
                     duration = float(ans.days)
-                    if lead.section_id.resource_calendar_id:
+                    if lead.section_id and lead.section_id.resource_calendar_id:
                         duration =  float(ans.days) * 24                        
                         new_dates = cal_obj.interval_get(cr,
                             uid,
diff --git a/addons/crm/crm_opportunity.py b/addons/crm/crm_opportunity.py
index 3e1fc24a803..4c84774e949 100644
--- a/addons/crm/crm_opportunity.py
+++ b/addons/crm/crm_opportunity.py
@@ -92,7 +92,7 @@ class crm_opportunity(osv.osv):
                             resource_id = resource_ids[0]
 
                     duration = float(ans.days)
-                    if opportunity.section_id.resource_calendar_id:
+                    if opportunity.section_id and opportunity.section_id.resource_calendar_id:
                         duration =  float(ans.days) * 24                        
                         new_dates = cal_obj.interval_get(cr,
                             uid,
diff --git a/addons/project_issue/project_issue.py b/addons/project_issue/project_issue.py
index 3f35913ae75..eaefffc18c4 100755
--- a/addons/project_issue/project_issue.py
+++ b/addons/project_issue/project_issue.py
@@ -84,10 +84,11 @@ class project_issue(osv.osv):
                     resource_id = False
                     if issue.user_id:
                         resource_ids = res_obj.search(cr, uid, [('user_id','=',issue.user_id.id)])
-                        resource_id = len(resource_ids) or resource_ids[0]
+                        if resource_ids and len(resource_ids):
+                            resource_id = resource_ids[0]
 
                     duration = float(ans.days)
-                    if issue.section_id.resource_calendar_id:
+                    if issue.section_id and issue.section_id.resource_calendar_id:
                         duration =  float(ans.days) * 24
                         new_dates = cal_obj.interval_get(cr,
                             uid,