Index: tol/btol/bmodel/estim.cpp
===================================================================
--- tol/btol/bmodel/estim.cpp	(revision e54fed57cdcee53632d6ae5a42399756b51aaf14)
+++ tol/btol/bmodel/estim.cpp	(revision 6d2858a2dcc863953065a9b85b8f8011dba80d6a)
@@ -1373,5 +1373,6 @@
   for(s=s_; s>=n+1; s--)
   {
-    if(Abs(rho.Data()(s-1))>1.E-6) { break; }
+    BDat r = _getACF(rho,s);
+    if(Abs(r)>1.E-6) { break; }
   }
   for(i=0; i<n; i++)