Index: trunk/psphot/src/psphotFitSourcesLinearStack.c
===================================================================
--- trunk/psphot/src/psphotFitSourcesLinearStack.c	(revision 30624)
+++ trunk/psphot/src/psphotFitSourcesLinearStack.c	(revision 31154)
@@ -163,7 +163,9 @@
     for (int i = 0; i < fitSources->n; i++) {
         pmSource *source = fitSources->data[i];
-        if (source->mode & PM_SOURCE_MODE_NONLINEAR_FIT) continue;
         pmModel *model = pmSourceGetModel (NULL, source);
-        pmSourceChisq (model, source->pixels, source->maskObj, source->variance, maskVal, COVAR_FACTOR);
+        if (!(source->mode & PM_SOURCE_MODE_NONLINEAR_FIT)) {
+	    model->nPar = 1; // LINEAR-only sources have 1 parameter; NONLINEAR sources have their original value
+	}
+        pmSourceChisq (model, source->pixels, source->maskObj, source->variance, maskVal);
     }
     psLogMsg ("psphot.ensemble", PS_LOG_MINUTIA, "get chisqs: %f sec (%d elements)\n", psTimerMark ("psphot.linear"), sparse->Nelem);