diff --git a/ChangeLog b/ChangeLog
index 1745f6622..b26e7d206 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2011-06-08  Francis Lachapelle  <flachapelle@inverse.ca>
+
+	* UI/WebServerResources/MailerUI.js (initMailer): added the Thread
+	column if missing from the columnsOrder user's defaults.
+
 2011-06-06  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
 	* OpenChange/*:
diff --git a/UI/WebServerResources/MailerUI.js b/UI/WebServerResources/MailerUI.js
index e2b8f3700..c7f4765ad 100644
--- a/UI/WebServerResources/MailerUI.js
+++ b/UI/WebServerResources/MailerUI.js
@@ -1905,7 +1905,9 @@ function initMailer(event) {
     if (!$(document.body).hasClassName("popup")) {
         Mailer.columnsOrder = UserDefaults["SOGoMailListViewColumnsOrder"];
         Mailer.sortByThread = UserDefaults["SOGoMailSortByThreads"] != null && parseInt(UserDefaults["SOGoMailSortByThreads"]) > 0;
-        if (!Mailer.sortByThread && Mailer.columnsOrder[0] == "Thread")
+        if (Mailer.sortByThread && Mailer.columnsOrder[0] != "Thread")
+            Mailer.columnsOrder = ["Thread"].concat(Mailer.columnsOrder);
+        else if (!Mailer.sortByThread && Mailer.columnsOrder[0] == "Thread")
             Mailer.columnsOrder.shift(); // drop the thread column
 
         // Restore sorting from user settings