Index: /branches/working-0711/ccl/lib/misc.lisp
===================================================================
--- /branches/working-0711/ccl/lib/misc.lisp	(revision 13439)
+++ /branches/working-0711/ccl/lib/misc.lisp	(revision 13440)
@@ -1119,5 +1119,5 @@
             do (incf total-psize psize))
 
-      (when threshold
+      (when (and data threshold)
         (setq data (sort data #'< :key #'cadddr))
         (loop while (< (/ (cadddr (car data)) total-psize) threshold)