diff -Naur orig/plugins/tasklist/tasklist-widget.c fixed/plugins/tasklist/tasklist-widget.c
--- orig/plugins/tasklist/tasklist-widget.c	2011-01-30 17:28:20.000000000 +0100
+++ fixed/plugins/tasklist/tasklist-widget.c	2011-02-01 10:21:04.000000000 +0100
@@ -1359,6 +1359,9 @@
   for (li = windows; li != NULL; li = li->next)
     xfce_tasklist_window_added (tasklist->screen, li->data, tasklist);
 
+  /* Fix for bug 7224 */
+  xfce_tasklist_gdk_screen_changed (tasklist->gdk_screen, tasklist);
+
   /* monitor gdk changes */
   g_signal_connect (G_OBJECT (tasklist->gdk_screen), "monitors-changed",
       G_CALLBACK (xfce_tasklist_gdk_screen_changed), tasklist);