Sematics of ARROW marker parameters changed between fuerte and hydro?

edit

Yes, this has changed and we also experienced the strange oval arrows when updating from fuerte. You´ll probably want to just update your code accordingly (should be straightforward in most cases).

/edit: Just looked up what we did:

   // add a movable arrow to the interactive marker
   visualization_msgs::Marker arrow;
   arrow.type = visualization_msgs::Marker::ARROW;
-  arrow.scale.z = 0.5;
+  arrow.scale.x = 0.5;
+  arrow.scale.y = 0.1;
+  arrow.scale.z = 0.1;
+
   arrow.color.r = 0.5;
   arrow.color.g = 0;
@@ -940,7 +943,7 @@
   } else {
     start_marker.type = visualization_msgs::Marker::ARROW;
-    start_marker.scale.x = 0.2;
-    start_marker.scale.y = 0.2;
-    start_marker.scale.z = 0.8;
+    start_marker.scale.x = 0.5;
+    start_marker.scale.y = 0.1;
+    start_marker.scale.z = 0.1;
   }

Looks like the wiki documentation you linked is wrong (at least for current ROS versions) and y and z are scaling the height/width, while x scales the length of the marker.

/edit2: I edited the description in the wiki to be correct:

Identity orientation points it along the +X axis. scale.x is the arrow length, scale.y is the arrow width and scale.z is the arrow height.