the listen usually should be done before any virtual host sections, so do this in the default config, too.

apache/apache.conf

@@ -10,7 +10,9 @@
 #   include Apache default/base configuration
 Include "@l_prefix@/etc/apache/apache.base"
 
+#   global network listening
+Listen   127.0.0.1:80
+
 #   override/extend with local configuration
 #Include "@l_prefix@/etc/apache/apache.vhost"
-Listen                 127.0.0.1:80