explicitly handling empty remaining hours since IE does not support :empty pseudo class

app/views/rb_tasks/_task.html.erb

@@ -8,12 +8,12 @@
     <div class="t"><%= assignee_name_or_empty(task) %></div>
     <div class="v"><%= assignee_id_or_empty(task) %></div>
   </div>
-  <div class="remaining_hours editable" fieldname="remaining_hours"><%= remaining_hours(task) %></div>
+  <div class="remaining_hours editable<%= ' empty' if remaining_hours(task).blank? %>" fieldname="remaining_hours"><%= remaining_hours(task) %></div>
   <div class="indicator"> </div>
   <div class="meta">
     <div class="story_id"><%= task.parent_id %></div>
     <div class="status_id"><%= task.status_id %></div>
     <div class="previous"><%= task.right_sibling.blank? ? '' : task.right_sibling.id %></div>
-    <%= render :partial => "shared/model_errors", :object => task.errors %>  
+    <%= render :partial => "shared/model_errors", :object => task.errors %>
   </div>
 </div>

assets/javascripts/app/task.js

@@ -75,6 +75,12 @@ RB.Task = (function ($) {
         this.$.children('.remaining_hours.editor').val('');
         this.$.children('.remaining_hours.editable').text('');
       }
+    },
+
+    refreshed : function () {
+      var remainingHours = this.$.children('.remaining_hours.editable');
+
+      remainingHours.toggleClass('empty', remainingHours.is(':empty'));
     }
   });
 }(jQuery));

assets/stylesheets/taskboard.css

@@ -204,7 +204,7 @@ See RB.Taskboard.initialize()
 #rb .issue .blocks {
   display:none;
 }
-#rb .issue .remaining_hours.editable:empty {
+#rb .issue .remaining_hours.editable.empty {
   display:none;
 }
 #rb .issue .indicator {