--- callbacks.c.orig	2007-04-05 13:23:19.734686048 +0200
+++ callbacks.c	2007-04-05 13:23:34.403521978 +0200
@@ -417,6 +417,10 @@
 void check_for_visor() {
 
 	GString *cadena;
+	if(!visor_ps) {
+		viewer_found=0;
+		return;
+	}
 	
 	if(check_visor(visor_ps->str)) { // if true, the file doesn't exist
 		cadena=g_string_new("");