Index: /trunk/clock_and_orbit/lib/clock_orbit_rtcm.c
===================================================================
--- /trunk/clock_and_orbit/lib/clock_orbit_rtcm.c	(revision 3727)
+++ /trunk/clock_and_orbit/lib/clock_orbit_rtcm.c	(revision 3728)
@@ -729,5 +729,5 @@
     break;
   case COTYPE_GPSCOMBINED:
-    if(!co) return -5;
+    if(!co) return GCOBR_NOCLOCKORBITPARAMETER;
     co->messageType = COTYPE_GPSCOMBINED;
     G_GPS_EPOCH_TIME(co->GPSEpochTime, co->NumberOfGPSSat)