Index: gtk2_ardour/editor_rulers.cc
===================================================================
--- gtk2_ardour/editor_rulers.cc	(revision 10948)
+++ gtk2_ardour/editor_rulers.cc	(working copy)
@@ -178,12 +178,12 @@
 
 	switch (direction) {
 	case GDK_SCROLL_UP:
-		temporal_zoom_step (true);
+		temporal_zoom_step (false);
 		handled = true;
 		break;
 
 	case GDK_SCROLL_DOWN:
-		temporal_zoom_step (false);
+		temporal_zoom_step (true);
 		handled = true;
 		break;