diff -u -r -d gpsd-1.07.orig/nmea_parse.c gpsd-1.07/nmea_parse.c
--- gpsd-1.07.orig/nmea_parse.c	2001-08-21 17:40:35.000000000 +0200
+++ gpsd-1.07/nmea_parse.c	2003-06-16 10:04:34.000000000 +0300
@@ -105,7 +105,8 @@
     int n, m, f = 4;
 
 
-    sscanf(field(sentence, 2), "%d", &n);
+    if (sscanf(field(sentence, 2), "%d", &n) < 1)
+	return;
     update_field_i(sentence, 3, &gNMEAdata.in_view, C_SAT);
 
     n = (n - 1) * 4;