Index: trunk/pois/src/poisFindStamps.c
===================================================================
--- trunk/pois/src/poisFindStamps.c	(revision 3802)
+++ trunk/pois/src/poisFindStamps.c	(revision 3813)
@@ -33,7 +33,7 @@
     if (stamps == NULL) {
 	stamps = psArrayAlloc(nsx * nsy);
-	// Initialise
+					// Initialise; should be done by psArrayAlloc
 	for (int i = 0; i < nsx * nsy; i++) {
-	    stamps->data[i] = poisStampAlloc();
+	    stamps->data[i] = NULL;
 	}
     }
@@ -44,4 +44,7 @@
 	for (int j = 0; j < nsy; j++) {
 	    poisStamp *stamp = stamps->data[num]; // The stamp
+	    if (stamp == NULL) {
+		stamp = stamps->data[num] = poisStampAlloc();
+	    }
 
 	    // Only find a new stamp if we need to