Index: linux-2.6.28-gentoo/net/netfilter/x_tables.c
===================================================================
--- linux-2.6.28-gentoo.orig/net/netfilter/x_tables.c
+++ linux-2.6.28-gentoo/net/netfilter/x_tables.c
@@ -354,8 +354,13 @@ int xt_check_match(struct xt_mtchk_param
 		       par->match->proto);
 		return -EINVAL;
 	}
-	if (par->match->checkentry != NULL && !par->match->checkentry(par))
-		return -EINVAL;
+	if (par->match->checkentry != NULL) {
+		printk("%s_tables: checkentry %p on %s\n",
+			xt_prefix[par->family], par->match->checkentry,
+			par->match->name);
+		if (!par->match->checkentry(par))
+			return -EINVAL;
+	}
 	return 0;
 }
 EXPORT_SYMBOL_GPL(xt_check_match);