--- a/toolkit/system/gnome/nsAlertsIconListener.cpp
+++ b/toolkit/system/gnome/nsAlertsIconListener.cpp
@@ -245,23 +245,25 @@ nsAlertsIconListener::StartRequest(const
   return il->LoadImage(imageUri, nsnull, nsnull, nsnull, this,
                        nsnull, nsIRequest::LOAD_NORMAL, nsnull, nsnull,
                        getter_AddRefs(mIconRequest));
 }
 
 void
 nsAlertsIconListener::SendCallback()
 {
-  mAlertListener->Observe(NULL, "alertclickcallback", mAlertCookie.get());
+  if (mAlertListener)
+    mAlertListener->Observe(NULL, "alertclickcallback", mAlertCookie.get());
 }
 
 void
 nsAlertsIconListener::SendClosed()
 {
-  mAlertListener->Observe(NULL, "alertfinished", mAlertCookie.get());
+  if (mAlertListener)
+    mAlertListener->Observe(NULL, "alertfinished", mAlertCookie.get());
 }
 
 nsresult
 nsAlertsIconListener::InitAlertAsync(const nsAString & aImageUrl,
                                      const nsAString & aAlertTitle, 
                                      const nsAString & aAlertText,
                                      PRBool aAlertTextClickable,
                                      const nsAString & aAlertCookie,