--- a/browser/components/feeds/src/FeedWriter.js
+++ b/browser/components/feeds/src/FeedWriter.js
@@ -39,17 +39,17 @@ function makeURI(aURLSpec, aCharset) {
             getService(Ci.nsIIOService);
   try {
     return ios.newURI(aURLSpec, aCharset, null);
   } catch (ex) { }
 
   return null;
 }
 
-const XML_NS = "http://www.w3.org/XML/1998/namespace"
+const XML_NS = "http://www.w3.org/XML/1998/namespace";
 const HTML_NS = "http://www.w3.org/1999/xhtml";
 const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
 const TYPE_MAYBE_FEED = "application/vnd.mozilla.maybe.feed";
 const TYPE_MAYBE_AUDIO_FEED = "application/vnd.mozilla.maybe.audio.feed";
 const TYPE_MAYBE_VIDEO_FEED = "application/vnd.mozilla.maybe.video.feed";
 const URI_BUNDLE = "chrome://browser/locale/feeds/subscribe.properties";
 
 const PREF_SELECTED_APP = "browser.feeds.handlers.application";
@@ -164,21 +164,25 @@ FeedWriter.prototype = {
     }
     catch (e) {
     }
     return "";
   },
 
   _setContentText: function FW__setContentText(id, text) {
     this._contentSandbox.element = this._document.getElementById(id);
-    this._contentSandbox.textNode = this._document.createTextNode(text);
+    this._contentSandbox.textNode = text.createDocumentFragment(this._contentSandbox.element);
     var codeStr =
       "while (element.hasChildNodes()) " +
       "  element.removeChild(element.firstChild);" +
       "element.appendChild(textNode);";
+    if (text.base) {
+      this._contentSandbox.spec = text.base.spec;
+      codeStr += "element.setAttributeNS('" + XML_NS + "', 'base', spec);";
+    }
     Cu.evalInSandbox(codeStr, this._contentSandbox);
     this._contentSandbox.element = null;
     this._contentSandbox.textNode = null;
   },
 
   /**
    * Safely sets the href attribute on an anchor tag, providing the URI 
    * specified can be loaded according to rules. 
@@ -356,26 +360,26 @@ FeedWriter.prototype = {
   /**
    * Writes the feed title into the preview document.
    * @param   container
    *          The feed container
    */
   _setTitleText: function FW__setTitleText(container) {
     if (container.title) {
       var title = container.title.plainText();
-      this._setContentText(TITLE_ID, title);
+      this._setContentText(TITLE_ID, container.title);
       this._contentSandbox.document = this._document;
       this._contentSandbox.title = title;
       var codeStr = "document.title = title;"
       Cu.evalInSandbox(codeStr, this._contentSandbox);
     }
 
     var feed = container.QueryInterface(Ci.nsIFeed);
     if (feed && feed.subtitle)
-      this._setContentText(SUBTITLE_ID, container.subtitle.plainText());
+      this._setContentText(SUBTITLE_ID, container.subtitle);
   },
 
   /**
    * Writes the title image into the preview document if one is present.
    * @param   container
    *          The feed container
    */
   _setTitleImage: function FW__setTitleImage(container) {
@@ -434,17 +438,21 @@ FeedWriter.prototype = {
       entry.QueryInterface(Ci.nsIFeedContainer);
 
       var entryContainer = this._document.createElementNS(HTML_NS, "div");
       entryContainer.className = "entry";
 
       // If the entry has a title, make it a link
       if (entry.title) {
         var a = this._document.createElementNS(HTML_NS, "a");
-        a.appendChild(this._document.createTextNode(entry.title.plainText()));
+        var span = this._document.createElementNS(HTML_NS, "span");
+        a.appendChild(span);
+        if (entry.title.base)
+          span.setAttributeNS(XML_NS, "base", entry.title.base.spec);
+        span.appendChild(entry.title.createDocumentFragment(a));
 
         // Entries are not required to have links, so entry.link can be null.
         if (entry.link)
           this._safeSetURIAttribute(a, "href", entry.link.spec);
 
         var title = this._document.createElementNS(HTML_NS, "h3");
         title.appendChild(a);
 

--- a/browser/components/feeds/test/Makefile.in
+++ b/browser/components/feeds/test/Makefile.in
@@ -13,14 +13,16 @@ include $(DEPTH)/config/autoconf.mk
 XPCSHELL_TESTS	= unit
 
 MOCHITEST_FILES =	bug408328-data.xml \
 		bug368464-data.xml \
 		test_bug494328.html \
 		bug494328-data.xml \
 		test_bug589543.html \
 		bug589543-data.xml \
+		test_bug436801.html \
+		bug436801-data.xml \
 		test_registerHandler.html \
 		valid-feed.xml \
 		valid-unsniffable-feed.xml \
 		$(NULL)
 
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/browser/components/feeds/test/bug436801-data.xml
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom" xml:base="http://www.example.com/">
+
+  <title type="xhtml" xml:base="/foo/bar/">
+    <div xmlns="http://www.w3.org/1999/xhtml">Example of a <em>special</em> feed (<img height="20px" src="baz.png" alt="base test sprite"/>)</div>
+  </title>
+
+  <subtitle type="html" xml:base="/foo/bar/">
+    <![CDATA[
+      With a <em>special</em> subtitle (<img height="20px" src="baz.png" alt="base test sprite"/>)
+    ]]>
+  </subtitle>
+
+  <link href="http://example.org/"/>
+
+  <updated>2010-09-02T18:30:02Z</updated>
+
+  <author>
+    <name>John Doe</name>
+  </author>
+
+  <id>urn:uuid:22906062-ecbd-46e2-b6a7-3039506a398f</id>
+
+  <entry>
+    <title type="xhtml" xml:base="/foo/bar/">
+      <div xmlns="http://www.w3.org/1999/xhtml">Some <abbr title="Extensible Hyper-text Mark-up Language">XHTML</abbr> examples (<img height="20px" src="baz.png" alt="base test sprite"/>)</div>
+    </title>
+    <id>urn:uuid:b48083a7-71a7-4c9c-8515-b7c0d22955e7</id>
+    <updated>2010-09-02T18:30:02Z</updated>
+    <summary>Some text.</summary>
+  </entry>
+
+  <entry>
+    <title type="html" xml:base="/foo/bar/">
+      <![CDATA[
+        Some <abbr title="Hyper-text Mark-up Language">HTML</abbr> examples (<img height="20px" src="baz.png" alt="base test sprite"/>)
+      ]]>
+    </title>
+    <id>urn:uuid:1424967a-280a-414d-b0ab-8b11c4ac1bb7</id>
+    <updated>2010-09-02T18:30:02Z</updated>
+    <summary>Some text.</summary>
+  </entry>
+
+</feed>

new file mode 100644
--- /dev/null
+++ b/browser/components/feeds/test/test_bug436801.html
@@ -0,0 +1,119 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=436801
+-->
+<head>
+  <title>Test feed preview subscribe UI</title>
+  <script type="text/javascript" src="/MochiKit/packed.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=436801">Mozilla Bug 436801</a>
+<p id="display"><iframe id="testFrame" src="bug436801-data.xml"></iframe></p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+
+SimpleTest.waitForExplicitFinish();
+
+addLoadEvent(function () {
+  netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
+  var doc = $("testFrame").contentDocument;
+
+  checkNode(doc.getElementById("feedTitleText"), [
+    "ELEMENT", "h1", { "xml:base": "http://www.example.com/foo/bar/" }, [
+      ["TEXT", "Example of a "],
+      ["ELEMENT", "em", [
+        ["TEXT", "special"],
+      ]],
+      ["TEXT", " feed ("],
+      ["ELEMENT", "img", { "src": "baz.png" }],
+      ["TEXT", ")"],
+    ]
+  ]);
+
+  checkNode(doc.getElementById("feedSubtitleText"), [
+    "ELEMENT", "h2", { "xml:base": "http://www.example.com/foo/bar/" }, [
+      ["TEXT", "With a "],
+      ["ELEMENT", "em", [
+        ["TEXT", "special"],
+      ]],
+      ["TEXT", " subtitle ("],
+      ["ELEMENT", "img", { "src": "baz.png" }],
+      ["TEXT", ")"],
+    ]
+  ]);
+
+  checkNode(doc.querySelector(".entry").firstChild.firstChild.firstChild, [
+    "ELEMENT", "span", { "xml:base": "http://www.example.com/foo/bar/" }, [
+      ["TEXT", "Some "],
+      ["ELEMENT", "abbr", { title: "Extensible Hyper-text Mark-up Language" }, [
+        ["TEXT", "XHTML"],
+      ]],
+      ["TEXT", " examples ("],
+      ["ELEMENT", "img", { "src": "baz.png" }],
+      ["TEXT", ")"],
+    ]
+  ]);
+
+  checkNode(doc.querySelectorAll(".entry")[1].firstChild.firstChild.firstChild, [
+    "ELEMENT", "span", { "xml:base": "http://www.example.com/foo/bar/" }, [
+      ["TEXT", "Some "],
+      ["ELEMENT", "abbr", { title: "Hyper-text Mark-up Language" }, [
+        ["TEXT", "HTML"],
+      ]],
+      ["TEXT", " examples ("],
+      ["ELEMENT", "img", { "src": "baz.png" }],
+      ["TEXT", ")"],
+    ]
+  ]);
+});
+
+addLoadEvent(SimpleTest.finish);
+
+function checkNode(node, schema) {
+  var typeName = schema.shift() + "_NODE";
+  var type = Node[typeName];
+  is(node.nodeType, type, "Node should be expected type " + typeName);
+  if (type == Node.TEXT_NODE) {
+    var text = schema.shift();
+    is(node.data, text, "Text should match");
+    return;
+  }
+  // type == Node.ELEMENT_NODE
+  var tag = schema.shift();
+  is(node.localName, tag, "Element should have expected tag");
+  while (schema.length) {
+    var val = schema.shift();
+    if (Array.isArray(val))
+      var childSchema = val;
+    else
+      var attrSchema = val;
+  }
+  if (attrSchema) {
+    var nsTable = {
+      xml: "http://www.w3.org/XML/1998/namespace",
+    };
+    for (var name in attrSchema) {
+      var [ns, nsName] = name.split(":");
+      var val = nsName ? node.getAttributeNS(nsTable[ns], nsName) :
+                node.getAttribute(name);
+      is(val, attrSchema[name], "Attribute " + name + " should match");
+    }
+  }
+  if (childSchema) {
+    var numChildren = node.childNodes.length;
+    is(childSchema.length, numChildren,
+       "Element should have expected number of children");
+    for (var i = 0; i < numChildren; i++)
+      checkNode(node.childNodes[i], childSchema[i]);
+  }
+}
+
+</script>
+</pre>
+</body>
+</html>