Impacted versions:
9.0 Community & 9.0 Enterprise

Steps to reproduce:
- Open up a V9 runbot
- Go to projects and click on the issues item, for example for the project 'Research & Development':
  ![image](https://cloud.githubusercontent.com/assets/6352350/13873686/65f2c31c-ecf3-11e5-917a-38df2832bd00.png)
- The project tasks view is opened in place of the project issues. (notice that this only happens every once in a while, about once in five attempts) Example:
  ![image](https://cloud.githubusercontent.com/assets/6352350/13873789/14798b64-ecf4-11e5-9b77-f2ad5d3a8adc.png)

Current behavior:
Every once in a while (about one out of five attempts) after clicking on the issues button it will open up the project tasks, not the issues.

Expected behavior:
When you click on the issues the view with all issues opens, not the view for all tasks.

""" Override to update the issue according to the email. """
        email_list = self.email_split(cr, uid, ids, msg, context=context)
        partner_ids = filter(None, self._find_partner_from_emails(cr, uid, ids, email_list, force_create=False, context=context))
        self.message_subscribe(cr, uid, ids, partner_ids, context=context)
        return super(project_issue, self).message_update(cr, uid, ids, msg, update_vals=update_vals, context=context)
    @api.cr_uid_ids_context
    @api.returns('mail.message', lambda value: value.id)
    def message_post(self, cr, uid, thread_id, subtype=None, context=None, **kwargs):
        """ Overrides mail_thread message_post so that we can set the date of last action field when
            a new message is posted on the issue.
        """
        if context is None:
            context = {}
        res = super(project_issue, self).message_post(cr, uid, thread_id, subtype=subtype, context=context, **kwargs)
        if thread_id and subtype:
            self.write(cr, SUPERUSER_ID, thread_id, {'date_action_last': fields.datetime.now()}, context=context)
        return res
class project(osv.Model):