diff --git a/common/content/autocommands.js b/common/content/autocommands.js
index 3246efcd..948a5e28 100644
--- a/common/content/autocommands.js
+++ b/common/content/autocommands.js
@@ -111,7 +111,7 @@ var AutoCommands = Module("autocommands", {
                     ["tr", {},
                         ["td", { colspan: "3" },
                             ["span", { highlight: "Title" }, hive.name],
-                            " ", /* E4X-FIXME: Filter is formatted E4X. */ String(hive.filter)]],
+                            " ", hive.filter.toJSONXML(modules)]],
                     ["tr", { style: "height: .5ex;" }],
                     iter(cmds(hive)).map(function ([event, items]) [
                         ["tr", { style: "height: .5ex;" }],
@@ -119,8 +119,7 @@ var AutoCommands = Module("autocommands", {
                             ["tr", {},
                                 ["td", { highlight: "Title", style: "padding-left: 1em; padding-right: 1em;" },
                                     i == 0 ? event : ""],
-                                // E4X-FIXME: ["td", {}, item.filter.toXML ? item.filter.toXML() : String(item.filter)],
-                                ["td", {}, String(item.filter)],
+                                ["td", {}, item.filter.toJSONXML ? item.filter.toJSONXML(modules) : String(item.filter)],
                                 ["td", {}, String(item.command)]]),
                         ["tr", { style: "height: .5ex;" }]]).toArray(),
                     ["tr", { style: "height: .5ex;" }],
diff --git a/common/content/dactyl.js b/common/content/dactyl.js
index 5130f915..3f0f0435 100644
--- a/common/content/dactyl.js
+++ b/common/content/dactyl.js
@@ -1294,7 +1294,7 @@ var Dactyl = Module("dactyl", XPCOM(Ci.nsISupportsWeakReference, ModuleBase), {
                                                                                            b.name)),
                                function ({ name, description })
                                [["dt", {}, name],
-                                ["dd", {}, template.linkifyHelp(description, true)]],
+                                ["dd", {}, template_.linkifyHelp(description, true)]],
                                "\n")]]);
         });
     },
diff --git a/common/modules/contexts.jsm b/common/modules/contexts.jsm
index a9d4fd1d..e6a014fc 100644
--- a/common/modules/contexts.jsm
+++ b/common/modules/contexts.jsm
@@ -13,7 +13,7 @@ lazyRequire("commands", ["ArgType", "CommandOption", "commands"]);
 lazyRequire("options", ["Option"]);
 lazyRequire("overlay", ["overlay"]);
 lazyRequire("storage", ["File"]);
-lazyRequire("template", ["template"]);
+lazyRequire("template", ["template", "template_"]);
 
 var Const = function Const(val) Class.Property({ enumerable: true, value: val });
 
@@ -78,10 +78,11 @@ var Group = Class("Group", {
         return update(siteFilter, {
             toString: function () this.filters.join(","),
 
-            toXML: function (modules) let (uri = modules && modules.buffer.uri)
-                template.map(this.filters,
-                             function (f) <span highlight={uri && f(uri) ? "Filter" : ""}>{f}</span>,
-                             <>,</>),
+            toJSONXML: function (modules) let (uri = modules && modules.buffer.uri)
+                template_.map(this.filters,
+                              function (f) ["span", { highlight: uri && f(uri) ? "Filter" : "" },
+                                                "toJSONXML" in f ? f.toJSONXML() : String(f)],
+                              ","),
 
             filters: Option.parse.sitelist(patterns)
         });
@@ -668,12 +669,12 @@ var Contexts = Module("contexts", {
                     {
                         names: ["-description", "-desc", "-d"],
                         description: "A description of this group",
-                        default: ["User-defined group"],
+                        default: "User-defined group",
                         type: CommandOption.STRING
                     },
                     {
                         names: ["-locations", "-locs", "-loc", "-l"],
-                        description: ["The URLs for which this group should be active"],
+                        description: "The URLs for which this group should be active",
                         default: ["*"],
                         type: CommandOption.LIST
                     },
@@ -799,7 +800,7 @@ var Contexts = Module("contexts", {
             context.keys = {
                 active: function (group) group.filter(uri),
                 text: "name",
-                description: function (g) <>{g.filter.toXML ? g.filter.toXML(modules) + <>&#xa0;</> : ""}{g.description || ""}</>
+                description: function (g) ["", g.filter.toJSONXML ? g.filter.toJSONXML(modules).concat("\u00a0") : "", g.description || ""]
             };
             context.completions = (active === undefined ? contexts.groupList : contexts.initializedGroups(active))
                                     .slice(0, -1);
diff --git a/common/modules/dom.jsm b/common/modules/dom.jsm
index d23932c9..1c16d10d 100644
--- a/common/modules/dom.jsm
+++ b/common/modules/dom.jsm
@@ -1570,6 +1570,8 @@ var DOM = Class("DOM", {
                 return args.toDOM(doc, namespaces, nodes);
             if (args instanceof Ci.nsIDOMNode)
                 return args;
+            if ("toJSONXML" in args)
+                args = args.toJSONXML();
 
             let [name, attr] = args;
 
@@ -1606,8 +1608,13 @@ var DOM = Class("DOM", {
 
             var args = Array.slice(args, 2);
             var vals = parseNamespace(name);
-            var elem = doc.createElementNS(vals[0] || namespaces[""],
-                                           name);
+            try {
+                var elem = doc.createElementNS(vals[0] || namespaces[""],
+                                               name);
+            }
+            catch (e) {
+                util.dump("FOO", vals[0] || namespaces[""], name);
+            }
 
             for (var key in attr)
                 if (!/^xmlns(?:$|:)/.test(key)) {
@@ -1688,7 +1695,7 @@ var DOM = Class("DOM", {
             if (args == "")
                 return "";
 
-            if (isinstance(args, ["String", "Number", _, DOM.DOMString]))
+            if (isinstance(args, ["String", "Number", "Boolean", _, DOM.DOMString]))
                 return indent +
                        DOM.escapeHTML(String(args), true);
 
@@ -1709,6 +1716,15 @@ var DOM = Class("DOM", {
                                .serializeToString(args)
                                .replace(/^/m, indent);
 
+            if ("toJSONXML" in args)
+                args = args.toJSONXML();
+
+            // Deal with common error case
+            if (args == null) {
+                util.reportError(Error("Unexpected null when processing XML."));
+                return "[NULL]";
+            }
+
             let [name, attr] = args;
 
             if (isFragment(args)) {