diff --git a/addons/website/models/ir_http.py b/addons/website/models/ir_http.py
index 44b3f771f62..8be35f5a9ae 100644
--- a/addons/website/models/ir_http.py
+++ b/addons/website/models/ir_http.py
@@ -74,7 +74,6 @@ class ir_http(orm.AbstractModel):
                         # to url without language so google doesn't see duplicate content
                         return request.redirect(path + '?' + request.httprequest.query_string)
                     return self.reroute(path)
-                return self._handle_exception(code=404)
         return super(ir_http, self)._dispatch()
 
     def reroute(self, path):
@@ -103,8 +102,8 @@ class ir_http(orm.AbstractModel):
         try:
             _, path = rule.build(arguments)
             assert path is not None
-        except Exception:
-            return self._handle_exception(werkzeug.exceptions.NotFound())
+        except Exception, e:
+            return self._handle_exception(e, code=404)
 
         if request.httprequest.method in ('GET', 'HEAD'):
             generated_path = werkzeug.url_unquote_plus(path)
@@ -136,55 +135,70 @@ class ir_http(orm.AbstractModel):
             if response.status_code == 304:
                 return response
 
-            response.mimetype = attach[0]['mimetype']
+            response.mimetype = attach[0]['mimetype'] or 'application/octet-stream'
             response.data = datas.decode('base64')
             return response
 
-    def _handle_exception(self, exception=None, code=500):
-        try:
+    def _handle_exception(self, exception, code=500):
+        # This is done first as the attachment path may
+        # not match any HTTP controller, so the request
+        # may not be website-enabled.
+        attach = self._serve_attachment()
+        if attach:
+            return attach
+
+        is_website_request = bool(getattr(request, 'website_enabled', False) and request.website)
+        if not is_website_request:
+            # Don't touch non website requests exception handling
             return super(ir_http, self)._handle_exception(exception)
-        except Exception:
+        else:
+            try:
+                response = super(ir_http, self)._handle_exception(exception)
+                if isinstance(response, Exception):
+                    exception = response
+                else:
+                    # if parent excplicitely returns a plain response, then we don't touch it
+                    return response
+            except Exception, e:
+                exception = e
 
-            attach = self._serve_attachment()
-            if attach:
-                return attach
+            values = dict(
+                exception=exception,
+                traceback=traceback.format_exc(exception),
+            )
+            code = getattr(exception, 'code', code)
 
-            if getattr(request, 'website_enabled', False) and request.website:
-                values = dict(
-                    exception=exception,
-                    traceback=traceback.format_exc(exception),
-                )
-                if exception:
-                    code = getattr(exception, 'code', code)
-                    if isinstance(exception, ir_qweb.QWebException):
-                        values.update(qweb_exception=exception)
-                        if isinstance(exception.qweb.get('cause'), openerp.exceptions.AccessError):
-                            code = 403
-                if code == 500:
-                    logger.error("500 Internal Server Error:\n\n%s", values['traceback'])
-                    if 'qweb_exception' in values:
-                        view = request.registry.get("ir.ui.view")
-                        views = view._views_get(request.cr, request.uid, exception.qweb['template'], request.context)
-                        to_reset = [v for v in views if v.model_data_id.noupdate is True]
-                        values['views'] = to_reset
-                elif code == 403:
-                    logger.warn("403 Forbidden:\n\n%s", values['traceback'])
+            if isinstance(exception, openerp.exceptions.AccessError):
+                code = 403
 
-                values.update(
-                    status_message=werkzeug.http.HTTP_STATUS_CODES[code],
-                    status_code=code,
-                )
+            if isinstance(exception, ir_qweb.QWebException):
+                values.update(qweb_exception=exception)
+                if isinstance(exception.qweb.get('cause'), openerp.exceptions.AccessError):
+                    code = 403
 
-                if not request.uid:
-                    self._auth_method_public()
+            if code == 500:
+                logger.error("500 Internal Server Error:\n\n%s", values['traceback'])
+                if 'qweb_exception' in values:
+                    view = request.registry.get("ir.ui.view")
+                    views = view._views_get(request.cr, request.uid, exception.qweb['template'], request.context)
+                    to_reset = [v for v in views if v.model_data_id.noupdate is True]
+                    values['views'] = to_reset
+            elif code == 403:
+                logger.warn("403 Forbidden:\n\n%s", values['traceback'])
 
-                try:
-                    html = request.website._render('website.%s' % code, values)
-                except Exception:
-                    html = request.website._render('website.http_error', values)
-                return werkzeug.wrappers.Response(html, status=code, content_type='text/html;charset=utf-8')
+            values.update(
+                status_message=werkzeug.http.HTTP_STATUS_CODES[code],
+                status_code=code,
+            )
 
-            raise
+            if not request.uid:
+                self._auth_method_public()
+
+            try:
+                html = request.website._render('website.%s' % code, values)
+            except Exception:
+                html = request.website._render('website.http_error', values)
+            return werkzeug.wrappers.Response(html, status=code, content_type='text/html;charset=utf-8')
 
 class ModelConverter(ir.ir_http.ModelConverter):
     def __init__(self, url_map, model=False, domain='[]'):
diff --git a/addons/website_forum/controllers/main.py b/addons/website_forum/controllers/main.py
index f20a0b1d5ef..89c4a33ed54 100644
--- a/addons/website_forum/controllers/main.py
+++ b/addons/website_forum/controllers/main.py
@@ -208,12 +208,16 @@ class WebsiteForum(http.Controller):
             }, context=context)
         return werkzeug.utils.redirect("/forum/%s/question/%s" % (slug(forum), new_question_id))
 
-    @http.route(['''/forum/<model("forum.forum"):forum>/question/<model("forum.post", "[('forum_id','=',forum[0])]"):question>'''], type='http', auth="public", website=True)
+    @http.route(['''/forum/<model("forum.forum"):forum>/question/<model("forum.post", "[('forum_id','=',forum[0]),('parent_id','=',False)]"):question>'''], type='http', auth="public", website=True)
     def question(self, forum, question, **post):
         cr, uid, context = request.cr, request.uid, request.context
         # increment view counter
         request.registry['forum.post'].set_viewed(cr, SUPERUSER_ID, [question.id], context=context)
 
+        if question.parent_id:
+            redirect_url = "/forum/%s/question/%s" % (slug(forum), slug(question.parent_id))
+            return werkzeug.utils.redirect(redirect_url, 301)
+
         filters = 'question'
         values = self._prepare_forum_values(forum=forum, searches=post)
         values.update({
diff --git a/openerp/http.py b/openerp/http.py
index ceddf234c1c..fe332c9ecb9 100644
--- a/openerp/http.py
+++ b/openerp/http.py
@@ -1251,7 +1251,10 @@ class Root(object):
             request = self.get_request(httprequest)
 
             def _dispatch_nodb():
-                func, arguments = self.nodb_routing_map.bind_to_environ(request.httprequest.environ).match()
+                try:
+                    func, arguments = self.nodb_routing_map.bind_to_environ(request.httprequest.environ).match()
+                except werkzeug.exceptions.HTTPException, e:
+                    return request._handle_exception(e)
                 request.set_handler(func, arguments, "none")
                 result = request.dispatch()
                 return result