diff --git a/mailnews/base/prefs/resources/content/AccountManager.xul b/mailnews/base/prefs/resources/content/AccountManager.xul
index 46bac0cc94a0..c7ff1bc369ed 100644
--- a/mailnews/base/prefs/resources/content/AccountManager.xul
+++ b/mailnews/base/prefs/resources/content/AccountManager.xul
@@ -22,7 +22,7 @@
 
 	<box orient="horizontal" flex="1" style="padding: 5px">
 		<box orient="vertical" flex="1">
-         <tree rdf:datasources="rdf:msgaccountmanager" flex="100%"
+         <tree rdf:datasources="rdf:msgaccountmanager" style="width:0px" flex="1"
           rdf:containment="http://home.netscape.com/NC-rdf#Settings"
           onselect="onAccountClick(event.target)" id="accounttree"
           class="inset"
diff --git a/mailnews/base/prefs/resources/content/SmtpServerList.xul b/mailnews/base/prefs/resources/content/SmtpServerList.xul
index 63aa32c96143..6251b8ee84c6 100644
--- a/mailnews/base/prefs/resources/content/SmtpServerList.xul
+++ b/mailnews/base/prefs/resources/content/SmtpServerList.xul
@@ -50,7 +50,10 @@
 </box>
 <box align="horizontal" style="min-height: 10em; min-width: 30em">
   <tree id="smtpTree" onselect="onSelectionChange(event);" class="inset" flex="1">
-    <treechildren id="smtpTreeChildren"/>
+    <treecolgroup>
+      <treecol flex="1"/>
+    </treecolgroup>
+    <treechildren id="smtpTreeChildren" flex="1"/>
   </tree>
   <box align="vertical">
     <button id="addButton"