Index: branches/release-33/lib/MT/Template/ContextHandlers.pm
===================================================================
--- branches/release-33/lib/MT/Template/ContextHandlers.pm (revision 1780)
+++ branches/release-33/lib/MT/Template/ContextHandlers.pm (revision 1781)
@@ -3639,5 +3639,5 @@
     return $ctx->error(MT->translate('sort_by="score" must be used in combination with namespace.'))
         if ((exists $args->{sort_by}) && ('score' eq $args->{sort_by}) && (!exists $args->{namespace}));
-    
+
     my $cfg = $ctx->{config};
     my $at = $ctx->{current_archive_type} || $ctx->{archive_type};
@@ -3966,4 +3966,5 @@
         $args{'sort'} = 'authored_on';
         if ($args->{sort_by}) {
+            $args->{sort_by} = 'ping_count' if $args->{sort_by} eq 'trackback_count';
             if ($class->has_column($args->{sort_by})) {
                 $args{sort} = $args->{sort_by};