--- apcupsd-3.14.9/src/gapcmon/gapcmon.c.timeout	2008-09-16 06:58:20.000000000 +0200
+++ apcupsd-3.14.9/src/gapcmon/gapcmon.c	2011-10-12 20:10:52.986362156 +0200
@@ -179,6 +179,54 @@ struct hostent * gethostname_re
 */
 static gboolean lg_graph_debug = FALSE;
 
+static GSList *timeout_list = NULL;
+
+static inline timeout_t * new_timeout(guint id, timeout_type_t type, void *data) {
+    timeout_t *timeout = (timeout_t *) malloc(sizeof(timeout_t));
+
+    timeout->id   = id;
+    timeout->type = type;
+    timeout->data = data;
+    return timeout;
+}
+
+/* callback will check if timeout is associated with window
+ * which is about to be destroyed and it will call g_source_remove 
+ * in order to prevent the callback associated with timeout to be executed 
+ */ 
+static void remove_timeout(gpointer tmo, gpointer data) {
+    timeout_t * timeout = (timeout_t *) tmo;
+    PGAPC_MONITOR monitor = (PGAPC_MONITOR) data;
+    int delete_timeout  = 0;
+
+    if (timeout == NULL) {
+        return;
+    }
+
+    switch (timeout->type) {
+    case GRAPH:
+        if (timeout->data == (void *) monitor->phs.plg) {
+            delete_timeout = 1;
+        }
+        break;
+    case MONITOR:
+        if (timeout->data == (void *) monitor) {
+            delete_timeout = 1;
+        }
+        break;
+
+    case HISTORY:
+        if (timeout->data == (void *) &(monitor->phs)) {
+            delete_timeout = 1;
+        }
+        break;
+    }
+    
+    if (delete_timeout) {
+        g_source_remove(timeout->id);
+        timeout_list = g_slist_remove(timeout_list, (gconstpointer) timeout);
+    }
+}
 
 /* ************************************************************************* */
 
@@ -1376,8 +1424,8 @@ static gint lg_graph_configure_event_cb 
     plg->x_range.i_minor_inc = plg->plot_box.width / plg->x_range.i_num_minor;
     plg->x_range.i_major_inc = plg->plot_box.width / plg->x_range.i_num_major;
 
-    g_timeout_add (250, (GSourceFunc) lg_graph_draw, plg);
-
+    guint tid = g_timeout_add (250, (GSourceFunc) lg_graph_draw, plg);
+    timeout_list = g_slist_append(timeout_list, new_timeout(tid, GRAPH, (void *) plg));
     return TRUE;
 }
 
@@ -1745,7 +1793,8 @@ static gboolean cb_monitor_automatic_ref
       return FALSE;                /* stop timers */
 
    if (pm->b_timer_control) {
-      g_timeout_add(100, (GSourceFunc) cb_monitor_refresh_control, pm);
+      guint tid = g_timeout_add(100, (GSourceFunc) cb_monitor_refresh_control, pm);
+      timeout_list = g_slist_append(timeout_list, new_timeout(tid, MONITOR, (void *) pm));
       return FALSE;
    }
 
@@ -4543,9 +4592,9 @@ static void cb_monitor_interface_button_
    }
 
    g_async_queue_push(pm->q_network, pm);
-   g_timeout_add(GAPC_REFRESH_FACTOR_ONE_TIME,
+   guint tid = g_timeout_add(GAPC_REFRESH_FACTOR_ONE_TIME,
       (GSourceFunc) cb_monitor_dedicated_one_time_refresh, pm);
-
+   timeout_list = g_slist_append(timeout_list, new_timeout(tid, MONITOR, (void *) pm));
    return;
 }
 
@@ -5174,6 +5223,9 @@ static void cb_monitor_interface_destroy
       g_source_remove(pm->tid_automatic_refresh);
    }
 
+   /* iterate through list of timers and remove all timers associated with this monitor */
+   g_slist_foreach(timeout_list, remove_timeout, (gpointer) pm);
+
    if (pm->tid_thread_qwork != NULL) {
       pm->b_thread_stop = TRUE;
       g_async_queue_push(pm->q_network, pm);
@@ -5537,9 +5589,9 @@ static gint gapc_monitor_history_page(PG
 
    /* collect one right away */
    pphs->b_startup = TRUE;
-   g_timeout_add((guint) (pm->d_refresh * GAPC_REFRESH_FACTOR_1K + 75),
+   guint tid = g_timeout_add((guint) (pm->d_refresh * GAPC_REFRESH_FACTOR_1K + 75),
       (GSourceFunc) cb_util_line_chart_refresh, pphs);
-
+   timeout_list = g_slist_append(timeout_list, new_timeout(tid, HISTORY, (void *) pphs));
    return i_page;
 }
 
@@ -5565,7 +5617,8 @@ static gboolean cb_util_line_chart_refre
       return FALSE;
 
    if (pm->b_graph_control) {
-      g_timeout_add(100, (GSourceFunc) cb_util_line_chart_refresh_control, pm);
+      guint tid = g_timeout_add(100, (GSourceFunc) cb_util_line_chart_refresh_control, pm);
+      timeout_list = g_slist_append(timeout_list, new_timeout(tid, MONITOR, (void *) pm));
       return FALSE;
    }
 
@@ -6392,6 +6445,7 @@ extern int main(int argc, char *argv[])
    PGAPC_CONFIG pcfg = NULL;
    GtkWidget *window = NULL;
 
+   timeout_list = g_slist_alloc();
    /*
     * Initialize GLib thread support, and GTK
     */
@@ -6435,5 +6489,6 @@ extern int main(int argc, char *argv[])
    gdk_flush();
    gdk_threads_leave();
 
+   g_slist_free(timeout_list);
    return (0);
 }
--- apcupsd-3.14.9/src/gapcmon/gapcmon.h	2011-10-12 20:12:54.584317583 +0200
+++ apcupsd-3.14.9/src/gapcmon/gapcmon.h.timeout	2011-10-12 20:14:10.965669911 +0200
@@ -403,6 +403,18 @@ typedef struct _System_Control_Data {
 
 } GAPC_CONFIG, *PGAPC_CONFIG;
 
+typedef enum {
+    GRAPH,
+    MONITOR,
+    HISTORY
+} timeout_type_t;
+
+typedef struct {
+    guint id;
+    timeout_type_t type;
+    void *data;
+} timeout_t;
+
 /* ************************************************************************* */
 
 #define GAPC_GLOSSARY  "<span size=\"xx-large\"><b>GAPCMON</b></span>\n \