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 get the reply_to of the parent project. """
        issues = self.browse(cr, SUPERUSER_ID, ids, context=context)
        project_ids = set([issue.project_id.id for issue in issues if issue.project_id])
        aliases = self.pool['project.project'].message_get_reply_to(cr, uid, list(project_ids), default=default, context=context)
        return dict((issue.id, aliases.get(issue.project_id and issue.project_id.id or 0, False)) for issue in issues)
    def message_get_suggested_recipients(self, cr, uid, ids, context=None):
        recipients = super(project_issue, self).message_get_suggested_recipients(cr, uid, ids, context=context)
        try:
            for issue in self.browse(cr, uid, ids, context=context):
                if issue.partner_id:
                    issue._message_add_suggested_recipient(recipients, partner=issue.partner_id, reason=_('Customer'))
                elif issue.email_from:
                    issue._message_add_suggested_recipient(recipients, email=issue.email_from, reason=_('Customer Email'))
        except AccessError:  # no 
            pass
        return recipients
    def email_split(self, cr, uid, ids, msg, context=None):
        email_list = tools.email_split((msg.get('to') or '') + ',' + (msg.get('cc') or ''))
        # ch
        issue_ids = self.browse(cr, uid, ids, context=context)
        aliases = [issue.project_id.alias_name for issue in issue_ids if issue.project_id]
        return filter(lambda x: x.split('@')[0] not in aliases, email_list)
    def message_new(self, cr, uid, msg, custom_values=None, context=None):