Index: /branches/eam_branches/psModules.20211028/src/imcombine/pmStack.c
===================================================================
--- /branches/eam_branches/psModules.20211028/src/imcombine/pmStack.c	(revision 41879)
+++ /branches/eam_branches/psModules.20211028/src/imcombine/pmStack.c	(revision 41880)
@@ -1649,7 +1649,7 @@
 		combined->mask->data.PS_TYPE_IMAGE_MASK_DATA[y][x] = blankMaskBits; // probably not needed since it was set above.
 		if (expmaps) {
-		    expmaps->image->F32[y][x] = NAN; // XXX should this value be NAN or 0?
-		    expmaps->variance->F32[y][x] = NAN;
-		    expmaps->mask->PS_TYPE_IMAGE_MASK_DATA[y][x] = 0;
+		    expmaps->image->data.F32[y][x] = NAN; // XXX should this value be NAN or 0?
+		    expmaps->variance->data.F32[y][x] = NAN;
+		    expmaps->mask->data.PS_TYPE_IMAGE_MASK_DATA[y][x] = 0;
 		}
 		continue;
@@ -1698,9 +1698,9 @@
 		expmaps->image->data.F32[y][x] = sum;
 	    }
-	    if (expNum) { expmaps->mask->data.F32[y][x] = Ne - Ns; }
+	    if (expmaps) { expmaps->mask->data.F32[y][x] = Ne - Ns; }
 	}
     }
     psFree(pixelData);
-    psFree(pixelVariance);
+    psFree(pixelVariances);
     psFree(expTime);
     return (true);