Index: trunk/psastro/src/psastroZeroPoint.c
===================================================================
--- trunk/psastro/src/psastroZeroPoint.c	(revision 21409)
+++ trunk/psastro/src/psastroZeroPoint.c	(revision 23989)
@@ -126,5 +126,8 @@
     // this analysis has too few data points to use the robust median method
     psStats *stats = psStatsAlloc (PS_STAT_CLIPPED_MEAN | PS_STAT_CLIPPED_STDEV);
-    psVectorStats (stats, dMag, NULL, NULL, 0);
+    if (!psVectorStats (stats, dMag, NULL, NULL, 0)) {
+	psError(PS_ERR_UNKNOWN, false, "failure to measure stats");
+	return false;
+    }
     fprintf (stderr, "zero point %f +/- %f using %d stars; transparency %f\n", stats->clippedMean, stats->clippedStdev, Npts, zeropt - stats->clippedMean);