diff --git a/node_modules/ace_tree/lib/ace_tree/virtual_renderer.js b/node_modules/ace_tree/lib/ace_tree/virtual_renderer.js
index a48b1181..fb683b4e 100644
--- a/node_modules/ace_tree/lib/ace_tree/virtual_renderer.js
+++ b/node_modules/ace_tree/lib/ace_tree/virtual_renderer.js
@@ -567,10 +567,6 @@ var VirtualRenderer = function(container, cellWidth, cellHeight) {
         var vertical   = this.$treeLayer;
         var horizontal = this.$horHeadingLayer;
         
-        var top = Math.max(this.scrollTop, 0);
-        var vRange = provider.getRange(top, top + this.$size.height);
-        var hRange = {size: 0}// horizontal.getRange(this.scrollLeft, this.scrollLeft + this.$size.width);
-
         var minHeight = this.$size.scrollerHeight;
         var maxHeight = provider.getTotalHeight();
         
@@ -604,6 +600,11 @@ var VirtualRenderer = function(container, cellWidth, cellHeight) {
         
         if (this.provider.getScrollTop() != this.scrollTop)
             this.scrollTop = this.provider.getScrollTop();
+            
+        var top = Math.max(this.scrollTop, 0);
+        var vRange = provider.getRange(top, top + this.$size.height);
+        var hRange = { size: 0 };// horizontal.getRange(this.scrollLeft, this.scrollLeft + this.$size.width);
+
         
         var vOffset  = this.scrollTop - vRange.size;
         var hOffset  = this.scrollLeft - hRange.size;
diff --git a/plugins/c9.ide.run/output.js b/plugins/c9.ide.run/output.js
index 00c9df7f..f5abf0eb 100644
--- a/plugins/c9.ide.run/output.js
+++ b/plugins/c9.ide.run/output.js
@@ -483,10 +483,9 @@ define(function(require, exports, module) {
                 
                 layout.on("eachTheme", function(e) {
                     var height = parseInt(ui.getStyleRule(".blackdg .row", "height"), 10) || 24;
-                    model.rowHeightInner = height - 1;
                     model.rowHeight = height;
                     
-                    if (e.changed) (datagrid).resize(true);
+                    if (e.changed) datagrid.resize(true);
                 });
 
                 model.$sorted = false;
@@ -510,7 +509,6 @@ define(function(require, exports, module) {
 
                 datagrid = new Tree(div);
                 datagrid.renderer.setTheme({ cssClass: "blackdg" });
-                datagrid.setOption("maxLines", 200);
                 datagrid.setDataProvider(model);
                 datagrid.edit = new TreeEditor(datagrid);
 
@@ -818,14 +816,18 @@ define(function(require, exports, module) {
                         return;
 
                     drawEnv();
-                    datagrid.resize();
-
                     model.session = currentSession;
                     if (!model.session.config.env)
                         model.session.config.env = {};
-
                     reloadModel();
-
+                    
+                    var rect = mnuEnv.opener.$ext.getBoundingClientRect();
+                    var top = rect.top;
+                    var bottom = window.innerHeight - rect.bottom;
+                    
+                    var maxRows = Math.floor(Math.max(top, bottom) / datagrid.model.rowHeight) - 2;
+                    datagrid.setOption("maxLines", maxRows);
+                    datagrid.resize();
                     mnuEnv.resize();
 
                     var node = datagrid.getFirstNode();
diff --git a/plugins/c9.ide.run/style.css b/plugins/c9.ide.run/style.css
index e9f93b1d..48de0972 100644
--- a/plugins/c9.ide.run/style.css
+++ b/plugins/c9.ide.run/style.css
@@ -94,7 +94,6 @@
 }
 .envcontainer .blackdg{
     border-top: 1px solid #363636;
-    max-height : 300px;
 }
 .tree-row.newenv:not(.selected) {
     color: rgb(151, 151, 151);