diff --git a/mailnews/base/resources/content/msgMail3PaneWindow.js b/mailnews/base/resources/content/msgMail3PaneWindow.js
index db97e5ea188..51acb077f56 100644
--- a/mailnews/base/resources/content/msgMail3PaneWindow.js
+++ b/mailnews/base/resources/content/msgMail3PaneWindow.js
@@ -611,6 +611,7 @@ function AddToSession()
 function InitPanes()
 {
     OnLoadFolderPane();
+    OnLoadThreadPane();
     SetupCommandUpdateHandlers();
 }
 
@@ -691,6 +692,35 @@ function OnLoadFolderPane()
     folderOutliner.addEventListener("click",FolderPaneOnClick,true);
 }
 
+// builds prior to 12-08-2001 did not have the labels column
+// in the thread pane.  so if a user ran an old build, and then
+// upgraded, they get the new column, and this causes problems.
+// We're trying to avoid a similar problem to bug #96979.
+// to work around this, we hide the column once, using the 
+// "mailnews.ui.threadpane.version" pref.
+function UpgradeThreadPaneUI()
+{
+  var labelCol;
+  var threadPaneUIVersion;
+
+  try {
+    threadPaneUIVersion = pref.getIntPref("mailnews.ui.threadpane.version");
+    if (threadPaneUIVersion == 1) {
+      labelCol = document.getElementById("labelCol");
+      labelCol.setAttribute("hidden", "true");
+      pref.setIntPref("mailnews.ui.threadpane.version", 2);
+    }
+	}
+  catch (ex) {
+    dump("UpgradeThreadPane: ex = " + ex + "\n");
+  }
+}
+
+function OnLoadThreadPane()
+{
+    UpgradeThreadPaneUI();
+}
+
 function GetFolderDatasource()
 {
     var folderOutliner = GetFolderOutliner();
diff --git a/mailnews/mailnews.js b/mailnews/mailnews.js
index 6d824ce5544..49421c16e03 100644
--- a/mailnews/mailnews.js
+++ b/mailnews/mailnews.js
@@ -332,6 +332,11 @@ pref("mail.server.default.retainBy", 1);
 // unread and total columns, see msgMail3PaneWindow.js
 pref("mail.ui.folderpane.version", 1);                                          
 
+// for manual upgrades of certain UI features.
+// 1 -> 2 is for the thread pane outliner landing, to hide the
+// labels column, see msgMail3PaneWindow.js
+pref("mailnews.ui.threadpane.version", 1);                                          
+
 //If set to a number greater than 0, msg compose windows will be recycled in order to open them quickly
 pref("mail.compose.max_recycled_windows", 0); 
 
diff --git a/modules/libpref/src/init/mailnews.js b/modules/libpref/src/init/mailnews.js
index 6d824ce5544..49421c16e03 100644
--- a/modules/libpref/src/init/mailnews.js
+++ b/modules/libpref/src/init/mailnews.js
@@ -332,6 +332,11 @@ pref("mail.server.default.retainBy", 1);
 // unread and total columns, see msgMail3PaneWindow.js
 pref("mail.ui.folderpane.version", 1);                                          
 
+// for manual upgrades of certain UI features.
+// 1 -> 2 is for the thread pane outliner landing, to hide the
+// labels column, see msgMail3PaneWindow.js
+pref("mailnews.ui.threadpane.version", 1);                                          
+
 //If set to a number greater than 0, msg compose windows will be recycled in order to open them quickly
 pref("mail.compose.max_recycled_windows", 0); 
 
diff --git a/profile/defaults/localstore.rdf b/profile/defaults/localstore.rdf
index b43c47bb164..ab7ec702f8b 100644
--- a/profile/defaults/localstore.rdf
+++ b/profile/defaults/localstore.rdf
@@ -5,6 +5,9 @@
   <RDF:Description about="chrome://messenger/content/messenger.xul#flaggedCol">
     <hidden>true</hidden>
   </RDF:Description>
+  <RDF:Description about="chrome://messenger/content/messenger.xul#labelCol">
+    <hidden>true</hidden>
+  </RDF:Description>
   <RDF:Description about="chrome://messenger/content/messenger.xul#unreadCol">
     <hidden>true</hidden>
   </RDF:Description>
@@ -33,6 +36,7 @@
     <NC:persist resource="chrome://messenger/content/messenger.xul#totalCol"/>
     <NC:persist resource="chrome://messenger/content/messenger.xul#OrderReceivedColumn"/>
     <NC:persist resource="chrome://messenger/content/messenger.xul#flaggedCol"/>
+    <NC:persist resource="chrome://messenger/content/messenger.xul#labelCol"/>
     <NC:persist resource="chrome://messenger/content/messenger.xul#folderUnreadCol"/>
     <NC:persist resource="chrome://messenger/content/messenger.xul#folderTotalCol"/>
     <NC:persist resource="chrome://messenger/content/messenger.xul#messengerWindow"/>
@@ -82,6 +86,9 @@
   <RDF:Description about="chrome://messenger/content/mail3PaneWindowVertLayout.xul#flaggedCol">
     <hidden>true</hidden>
   </RDF:Description>
+  <RDF:Description about="chrome://messenger/content/mail3PaneWindowVertLayout.xul#labelCol">
+    <hidden>true</hidden>
+  </RDF:Description>
   <RDF:Description about="chrome://messenger/content/mail3PaneWindowVertLayout.xul#unreadCol">
     <hidden>true</hidden>
   </RDF:Description>
@@ -110,6 +117,7 @@
     <NC:persist resource="chrome://messenger/content/mail3PaneWindowVertLayout.xul#totalCol"/>
     <NC:persist resource="chrome://messenger/content/mail3PaneWindowVertLayout.xul#OrderReceivedColumn"/>
     <NC:persist resource="chrome://messenger/content/mail3PaneWindowVertLayout.xul#flaggedCol"/>
+    <NC:persist resource="chrome://messenger/content/mail3PaneWindowVertLayout.xul#labelCol"/>
     <NC:persist resource="chrome://messenger/content/mail3PaneWindowVertLayout.xul#folderUnreadCol"/>
     <NC:persist resource="chrome://messenger/content/mail3PaneWindowVertLayout.xul#folderTotalCol"/>
   </RDF:Description>