Index: trunk/psphot/src/psphotApResid.c
===================================================================
--- trunk/psphot/src/psphotApResid.c	(revision 21519)
+++ trunk/psphot/src/psphotApResid.c	(revision 23989)
@@ -355,12 +355,15 @@
 
         if (j > 2) {
-            bool status = true;
-            status &= psVectorStats (statsS, dASubset, NULL, mkSubset, 0xff);
-            status &= psVectorStats (statsM, dMSubset, NULL, mkSubset, 0xff);
-            if (!status) { psErrorClear (); }
+            if (!psVectorStats (statsS, dASubset, NULL, mkSubset, 0xff)) {
+		psError(PS_ERR_UNKNOWN, false, "failure to measure stats");
+		return false;
+	    }
+            if (!psVectorStats (statsM, dMSubset, NULL, mkSubset, 0xff)) {
+		psError(PS_ERR_UNKNOWN, false, "failure to measure stats");
+		return false;
+	    }
             dSo->data.F32[i] = statsS->robustStdev;
             dMo->data.F32[i] = statsM->sampleMean;
             dRo->data.F32[i] = statsS->robustStdev / statsM->sampleMean;
-            //      fprintf (stderr, "%d (%d) : sys: %f, phot: %f, rat: %f\n", i, j, dSo->data.F32[i], dMo->data.F32[i], dRo->data.F32[i]);
         } else {
             dSo->data.F32[i] = NAN;
@@ -375,6 +378,6 @@
     psStats *stats = psStatsAlloc (PS_STAT_SAMPLE_MEDIAN);
     if (!psVectorStats (stats, dRo, NULL, NULL, 0)) {
-        // XXX better testing of raised error
-        psErrorClear();
+	psError(PS_ERR_UNKNOWN, false, "failure to measure stats");
+	return false;
     }