Index: trunk/ppStack/src/ppStackConvolve.c
===================================================================
--- trunk/ppStack/src/ppStackConvolve.c	(revision 26080)
+++ trunk/ppStack/src/ppStackConvolve.c	(revision 26104)
@@ -128,10 +128,29 @@
         pmHDU *hdu = readout->parent->parent->parent->hdu; // HDU for convolved image
         assert(hdu);
-        ppStackWriteImage(options->convImages->data[i], hdu->header, readout->image, config);
+        if (!ppStackWriteImage(options->convImages->data[i], hdu->header, readout->image, config)) {
+            psError(PS_ERR_IO, false, "Unable to write convolved image %d", i);
+            psFree(fpaList);
+            psFree(cellList);
+            psFree(rng);
+            return false;
+        }
         psMetadata *maskHeader = psMetadataCopy(NULL, hdu->header); // Copy of header, for mask
         pmConfigMaskWriteHeader(config, maskHeader);
-        ppStackWriteImage(options->convMasks->data[i], maskHeader, readout->mask, config);
+        if (!ppStackWriteImage(options->convMasks->data[i], maskHeader, readout->mask, config)) {
+            psError(PS_ERR_IO, false, "Unable to write convolved mask %d", i);
+            psFree(fpaList);
+            psFree(cellList);
+            psFree(rng);
+            psFree(maskHeader);
+            return false;
+        }
         psFree(maskHeader);
-        ppStackWriteImage(options->convVariances->data[i], hdu->header, readout->variance, config);
+        if (!ppStackWriteImage(options->convVariances->data[i], hdu->header, readout->variance, config)) {
+            psError(PS_ERR_IO, false, "Unable to write convolved variance %d", i);
+            psFree(fpaList);
+            psFree(cellList);
+            psFree(rng);
+            return false;
+        }
 #ifdef TESTING
         {
Index: trunk/ppStack/src/ppStackFiles.c
===================================================================
--- trunk/ppStack/src/ppStackFiles.c	(revision 26080)
+++ trunk/ppStack/src/ppStackFiles.c	(revision 26104)
@@ -181,5 +181,9 @@
         return false;
     }
-    psFitsClose(fits);
+    if (!psFitsClose(fits)) {
+        psError(PS_ERR_IO, false, "Unable to close FITS image %s.", resolved);
+        psFree(resolved);
+        return false;
+    }
     psFree(resolved);
     return true;