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.

addons/project_issue/project_issue.py
""" Overrides mail_thread message_new that is called by the mailgateway
            through message_process.
            This override updates the document according to the email.
        """
        # re
        # do 
        # wa
        # fo
        create_context = dict(context or {})
        create_context['default_user_id'] = False
        if custom_values is None:
            custom_values = {}
        context = dict(context or {}, state_to='draft')
        defaults = {
            'name':  msg.get('subject') or _("No Subject"),
            'email_from': msg.get('from'),
            'email_cc': msg.get('cc'),
            'partner_id': msg.get('author_id', False),
        }
        defaults.update(custom_values)
        res_id = super(project_issue, self).message_new(cr, uid, msg, custom_values=defaults, context=create_context)
        email_list = self.email_split(cr, uid, [res_id], msg, context=context)
        partner_ids = filter(None, self._find_partner_from_emails(cr, uid, [res_id], email_list, force_create=False, context=context))
        self.message_subscribe(cr, uid, [res_id], partner_ids, context=context)
        return res_id
    def message_update(self, cr, uid, ids, msg, update_vals=None, context=None):