diff -r daaf445d707b apps/common/main/lib/mods/perfect-scrollbar.js
--- a/apps/common/main/lib/mods/perfect-scrollbar.js	Mon Jun 15 15:25:53 2015 +0300
+++ b/apps/common/main/lib/mods/perfect-scrollbar.js	Thu Jun 18 13:29:36 2015 +0300
// change thumb event
@@ -197,6 +197,10 @@
         }
 
         updateScrollbarCss();
+
+        if (settings.onChange) {
+            settings.onChange(this);
+        }
       };
 
       var bindMouseScrollXHandler = function () {
