Index: roundcubemail/skins/default/mail.css
===================================================================
--- roundcubemail/skins/default/mail.css	(revision 2308)
+++ roundcubemail/skins/default/mail.css	(working copy)
@@ -547,6 +547,30 @@
   cursor: pointer;
 }
 
+#messagelist tr td div
+{
+  display: table-cell; /* For FireFox and Opera */
+  display: inline-block; /* For Opera and IE */ 
+  width: 15px;
+  height: 15px;
+}
+
+#messagelist tr td div.collapsed,
+#messagelist tr td div.expanded
+{
+  cursor: pointer;
+}
+
+#messagelist  tr td div.collapsed
+{
+  background: url(images/icons/collapsed.png) center center no-repeat;
+}
+
+#messagelist  tr td div.expanded
+{
+  background: url(images/icons/expanded.png) center center no-repeat;
+}
+
 #messagelist tbody tr td.flag img:hover,
 #messagelist thead tr td.flag img
 {