diff --git a/models/payment_transaction.py b/models/payment_transaction.py
index 3217f00..8092f48 100755
--- a/models/payment_transaction.py
+++ b/models/payment_transaction.py
@@ -32,7 +32,16 @@ class PaymentTransaction(models.Model):
                                       string='Online payment', copy=False, readonly=True)
 
     reference2=fields.Char('type',compute='compute_reference')
+
+    invoice_bug=fields.Boolean(string="invoice bug", compute='_compute_invoice_bug',store=True)
     
+    def _compute_invoice_bug(self):
+        for rec in self:
+            rec.invoice_bug=False
+            for invoice in rec.invoice_ids:
+                if rec.state in ['done','authorized'] and invoice.payment_state!='paid' and invoice.state=='posted':
+                    rec.invoice_bug=True
+
     def compute_reference(self):
         for rec in self:
             rec.reference2='Participation'