--- a/suite/common/pref/pref-tabs.xul
+++ b/suite/common/pref/pref-tabs.xul
@@ -33,23 +33,31 @@
                   name="browser.tabs.loadGroup"
                   type="int"/>
       <preference id="browser.tabs.opentabfor.middleclick"
                   name="browser.tabs.opentabfor.middleclick"
                   type="bool"/>
       <preference id="browser.tabs.opentabfor.urlbar"
                   name="browser.tabs.opentabfor.urlbar"
                   type="bool"/>
+      <preference id="suite.manager.dataman.openAsDialog"
+                  name="suite.manager.dataman.openAsDialog"
+                  inverted="true"
+                  type="bool"/>
+      <preference id="suite.manager.addons.openAsDialog"
+                  name="suite.manager.addons.openAsDialog"
+                  inverted="true"
+                  type="bool"/>
     </preferences>
 
       <groupbox id="generalTabPreferences" align="start">
         <caption label="&tabDisplay.label;"/>
         <checkbox id="tabStrip"
                   label="&autoHide.label;"
-                  accesskey="&autoHide.accesskey;"
+                  accesskey="&autoHide.accesskey2;"
                   preference="browser.tabs.autoHide"/>
         <checkbox id="tabBackground"
                   label="&background.label;"
                   accesskey="&background.accesskey;"
                   preference="browser.tabs.loadInBackground"/>
         <checkbox id="tabWarnOnClose"
                   label="&warnOnClose.label;"
                   accesskey="&warnOnClose.accesskey;"
@@ -80,10 +88,22 @@
                     label="&middleClick.label;"
                     accesskey="&middleClick.accesskey;"
                     preference="browser.tabs.opentabfor.middleclick"/>
           <checkbox id="urlBar"
                     label="&urlbar.label;"
                     accesskey="&urlbar.accesskey;"
                     preference="browser.tabs.opentabfor.urlbar"/>
       </groupbox>
+
+      <groupbox id="useManagersPreferences" align="start">
+        <caption label="&openManagers.label;"/>
+          <checkbox id="openDataManager"
+                    label="&openDataManager.label;"
+                    accesskey="&openDataManager.accesskey;"
+                    preference="suite.manager.dataman.openAsDialog"/>
+          <checkbox id="openAddOnsManager"
+                    label="&openAddOnsManager.label;"
+                    accesskey="&openAddOnsManager.accesskey;"
+                    preference="suite.manager.addons.openAsDialog"/>
+      </groupbox>
   </prefpane>
 </overlay>

--- a/suite/locales/en-US/chrome/common/help/cs_nav_prefs_navigator.xhtml
+++ b/suite/locales/en-US/chrome/common/help/cs_nav_prefs_navigator.xhtml
@@ -505,16 +505,28 @@
         <kbd class="mac">Cmd</kbd><kbd class="noMac">Ctrl</kbd>+<kbd
         class="mac">Return</kbd><kbd class="noMac">Enter</kbd> in the Location
         bar</strong>: Select this to open a Web page in a new tab when you type
         the URL of the page in the Location Bar and press
         <kbd class="mac">Cmd</kbd><kbd class="noMac">Ctrl</kbd>+<kbd
         class="mac">Return</kbd><kbd class="noMac">Enter</kbd>.</li>
     </ul>
   </li>
+  <li><strong>Open in a new tab instead of a stand-alone window</strong>:
+    <ul>
+      <!-- link to Data Manager description once bug 599097 is fixed -->
+      <li><strong>Data Manager</strong>: Select this to open the Data Manager
+        in a browser tab. If unchecked, it will open in a separate dialog
+        window.</li>
+      <li><strong>Add-ons Manager</strong>: Select this to open the
+        <a href="customize_help.xhtml#using_the_add-ons_manager">Add-ons
+        Manager</a> in a browser tab. If unchecked, it will open in a separate
+        dialog window.</li>
+    </ul>
+  </li>
 </ul>
 
 <p>[<a href="#navigator_preferences">Return to beginning of section</a>]</p>
 
 <h2 id="link_behavior">Browser Preferences - Link Behavior</h2>
 
 <p>This section describes how to use the Link Behavior preferences panel. If
   you&apos;re not already viewing it, follow these steps:</p>

--- a/suite/locales/en-US/chrome/common/help/customize_help.xhtml
+++ b/suite/locales/en-US/chrome/common/help/customize_help.xhtml
@@ -1150,16 +1150,21 @@
 
 <ul>
   <li>Open the Tools menu, then select Add-ons Manager.</li>
   <li>Open the <span class="mac">&brandShortName;</span><span
     class="noMac">Edit</span> menu and choose Preferences, expand the Advanced
     category, click Software Installation, then Manage Add-ons.</li>
 </ul>
 
+<p>The Add-ons Manager opens either in its own dialog window or in a browser
+  tab. You can modify this behavior in the <a
+  href="cs_nav_prefs_navigator.xhtml#tabbed_browsing">Tabbed Browsing</a>
+  preference settings.</p>
+
 <div class="contentsBox">In this section:
   <ul>
     <li><a href="#searching_for_add-ons">Searching for Add-ons</a></li>
     <li><a href="#the_get_add-ons_panel">The Get Add-ons panel</a></li>
     <li><a href="#the_extensions_panel">The Extensions panel</a></li>
     <li><a href="#the_appearance_panel">The Appearance panel</a></li>
     <li><a href="#the_plugins_panel">The Plugins panel</a></li>
     <li><a href="#the_languages_panel">The Languages panel</a></li>

--- a/suite/locales/en-US/chrome/common/pref/pref-tabs.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-tabs.dtd
@@ -1,20 +1,29 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <!ENTITY tabHeader.label "Tabbed Browsing">
+
 <!ENTITY tabDisplay.label "Tab Display">
 <!ENTITY autoHide.label "Hide the tab bar when only one tab is open">
-<!ENTITY autoHide.accesskey "d">
+<!ENTITY autoHide.accesskey2 "e">
 <!ENTITY background.label "Switch to new tabs opened from links">
 <!ENTITY background.accesskey "S">
 <!ENTITY warnOnClose.label "Warn me when closing a window with multiple tabs">
 <!ENTITY warnOnClose.accesskey "W">
 <!ENTITY relatedAfterCurrent.label "Open related tabs after current tab">
 <!ENTITY relatedAfterCurrent.accesskey "O">
+
 <!ENTITY loadGroup.label "When opening a bookmark group">
 <!ENTITY loadGroupAppend.label "Add tabs">
 <!ENTITY loadGroupAppend.accesskey "A">
 <!ENTITY loadGroupReplace.label "Replace existing tabs">
 <!ENTITY loadGroupReplace.accesskey "R">
+
 <!ENTITY openTabs.label "Open tabs instead of windows for">
+
+<!ENTITY openManagers.label "Open in a new tab instead of a stand-alone window">
+<!ENTITY openDataManager.label "Data Manager">
+<!ENTITY openDataManager.accesskey "D">
+<!ENTITY openAddOnsManager.label "Add-ons Manager">
+<!ENTITY openAddOnsManager.accesskey "n">