diff --git a/lib/mess/parser.js b/lib/mess/parser.js
index f0d588c..17d882b 100644
--- a/lib/mess/parser.js
+++ b/lib/mess/parser.js
@@ -775,7 +775,7 @@ mess.Parser = function Parser(env) {
                         elements.push(e);
                     } else if (z) {
                         if (zoom) {
-                            zoom.intersect(z);
+                            zoom.intersection(z);
                         } else {
                             zoom = z;
                         }
diff --git a/lib/mess/renderer.js b/lib/mess/renderer.js
index 5a5dce5..6d584d2 100644
--- a/lib/mess/renderer.js
+++ b/lib/mess/renderer.js
@@ -41,7 +41,7 @@ mess.Renderer = function Renderer(env) {
                     var group = this.group();
                     var autodetect = _.filter(m.Layer, function(l) { return !l.srs; });
                     _.each(autodetect, function(l) {
-                        var finish = group();
+                        var next = group();
                         Step(
                             function() {
                                 fs.readdir(path.dirname(l.Datasource.file), this);
@@ -61,11 +61,9 @@ mess.Renderer = function Renderer(env) {
                                 if (!err) {
                                     try {
                                         l.srs = require('srs').parse(srs).proj4;
-                                    } catch (err) {
-                                        finish(err);
-                                    }
+                                    } catch (err) {}
                                 }
-                                finish(err);
+                                next(err);
                             }
                         );
                     });
@@ -183,6 +181,7 @@ mess.Renderer = function Renderer(env) {
                     var options = {},
                         group = this.group();
                     for (var i = 0, l = results.length; i < l; i++) {
+                        var next = group();
                         new mess.Parser(_.extend(_.extend({
                             filename: results[i][0]
                         }, that.env), this.env)).parse(results[i][1],
@@ -192,7 +191,7 @@ mess.Renderer = function Renderer(env) {
                                 throw err;
                             } else {
                                 try {
-                                    group()(err, [
+                                    next(err, [
                                         results[i][0],
                                         tree]);
                                     return;
diff --git a/lib/mess/tree/ruleset.js b/lib/mess/tree/ruleset.js
index 2f434ef..be006ee 100644
--- a/lib/mess/tree/ruleset.js
+++ b/lib/mess/tree/ruleset.js
@@ -125,17 +125,7 @@ tree.Ruleset.prototype = {
 
                     // Create a new object for each so that we can have different
                     // elements and filters in the selector.
-                    var instance = new tree.Selector();
-                    instance.elements = parent.elements.concat(selector.elements);
-                    instance.filters = parent.filters.concat(selector.filters);
-                    if (parent.zoom && selector.zoom) {
-                        instance.zoom = parent.zoom.clone().intersection(selector.zoom);
-                    } else if (parent.zoom || selector.zoom) {
-                        instance.zoom = (parent.zoom || selector.zoom).clone()
-                    }
-                    instance.attachment = selector.attachment;
-                    instance.index = selector.index;
-
+                    var instance = parent.clone().merge(selector);
                     selectors.push(instance);
                 }
             }
diff --git a/lib/mess/tree/selector.js b/lib/mess/tree/selector.js
index f7bc9ff..6f03344 100644
--- a/lib/mess/tree/selector.js
+++ b/lib/mess/tree/selector.js
@@ -18,7 +18,18 @@ tree.Selector.prototype.clone = function() {
         obj.zoom = this.zoom.clone();
     }
     return obj;
-}
+};
+
+tree.Selector.prototype.merge = function(obj) {
+    Array.prototype.push.apply(this.elements, obj.elements);
+    Array.prototype.push.apply(this.filters, obj.filters);
+    if (obj.attachment) this.attachment = obj.attachment;
+    this.index = obj.index;
+
+    if (this.zoom && obj.zoom) this.zoom.intersection(obj.zoom);
+    else if (obj.zoom) this.zoom = obj.zoom.clone();
+    return this;
+};
 
 /**
  * Determine the specificity of this selector