Don't throw away fully loaded supermodels in between simulations or refresh tabs when not looking at them.

app/lib/LevelLoader.coffee

@@ -107,6 +107,7 @@ module.exports = class LevelLoader extends CocoClass
   # Things to do when either the Session or Supermodel load
 
   update: =>
+    return if @destroyed
     @notifyProgress()
 
     return if @updateCompleted

app/lib/simulator/Simulator.coffee

@@ -44,7 +44,7 @@ module.exports = class Simulator extends CocoClass
     return @handleNoGamesResponse() if jqXHR.status is 204
     @trigger 'statusUpdate', 'Setting up simulation!'
     @task = new SimulationTask(taskData)
-    @supermodel = new SuperModel()
+    @supermodel ?= new SuperModel()
     @god = new God maxWorkerPoolSize: 1, maxAngels: 1  # Start loading worker.
 
     @levelLoader = new LevelLoader supermodel: @supermodel, levelID: @task.getLevelName(), sessionID: @task.getFirstSessionID(), headless: true

app/views/play/ladder_view.coffee

@@ -75,11 +75,17 @@ module.exports = class LadderView extends RootView
     @sessions.fetch({"success": @refreshViews})
 
   refreshViews: =>
-    return if @destroyed or application.userIsIdle or new Date() - 2000 < @lastRefreshTime
-    @lastRefreshTime = new Date()
-    @ladderTab.refreshLadder()
-    @myMatchesTab.refreshMatches()
-    console.log "Refreshing ladder and matches views."
+    return if @destroyed or application.userIsIdle
+    if @$el.find("#ladder.active").length
+      return if new Date() - 2000 < @lastLadderRefreshTime
+      @lastLadderRefreshTime = new Date()
+      @ladderTab.refreshLadder()
+      console.log "Refreshing ladder."
+    if @$el.find("#my-matches.active").length
+      return if new Date() - 2000 < @lastMatchesRefreshTime
+      @lastMatchesRefreshTime = new Date()
+      @myMatchesTab.refreshMatches()
+      console.log "Refreshing matches view."
 
   onIdleChanged: (e) ->
     @refreshViews() unless e.idle