--- wget-1.9.1/src/retr.c
+++ wget-1.9.1/src/retr.c
@@ -288,7 +288,9 @@
 {
   double dlrate;
 
-  assert (msecs >= 0);
+  if (msecs < 0) 
+	msecs = 0; /* XXX: sometimes X86_64 goes backwards in time */
+
   assert (bytes >= 0);
 
   if (msecs == 0)