--- src/libdspam.c	2006-07-17 02:14:02.000000000 +0200
+++ src/libdspam.fix_bnr_debug.c	2007-12-10 20:33:53.905085288 +0100
@@ -986,8 +986,10 @@
     if (CTX->flags & DSF_NOISE) {
       nobnr_result = _ds_calc_result(CTX, heap_nobnr, diction);
 
-      if (CTX->factors) 
+      if (CTX->factors) {
         _ds_factor_destroy(CTX->factors);
+	CTX->factors = NULL;
+      }
       CTX->result = x;
       CTX->probability = DSP_UNCALCULATED;
     }