diff --git a/C/iopreds.c b/C/iopreds.c
index 3ae4dfd98..41434ebb9 100644
--- a/C/iopreds.c
+++ b/C/iopreds.c
@@ -2287,8 +2287,12 @@ StreamName(int i)
       return(MkAtomTerm(LookupAtom("pipe")));
     if (Stream[i].status & InMemory_Stream_f)
       return(MkAtomTerm(LookupAtom("charsio")));
-    else
-      return(MkAtomTerm(Stream[i].u.file.name));
+    else {
+      if (yap_flags[LANGUAGE_MODE_FLAG] == ISO_CHARACTER_ESCAPES) {
+	return(Stream[i].u.file.user_name);
+      } else
+	return(MkAtomTerm(Stream[i].u.file.name));
+    }
 }
 
 static Int
@@ -2301,6 +2305,9 @@ init_cur_s (void)
     Term t1, t2;
 
     i = CheckStream (t3, Input_Stream_f|Output_Stream_f, "current_stream/3");
+    if (i < 0) {
+      return(FALSE);
+    }
     t1 = StreamName(i);
     t2 = (Stream[i].status & Input_Stream_f ?
 	  MkAtomTerm (AtomRead) :
@@ -2483,6 +2490,46 @@ p_past_eof (void)
   return(Stream[sno].status & Eof_Stream_f);
 }
 
+static Int
+p_peek_byte (void)
+{				/* at_end_of_stream */
+  /* the next character is a EOF */ 
+  int sno = CheckStream (ARG1, Input_Stream_f, "peek/2");
+  StreamDesc *s;
+  Int ocharcount, olinecount, olinepos;
+  Int status;
+  Int ch;
+
+  if (sno < 0)
+    return(FALSE);
+  status = Stream[sno].status;
+  if (!(status & Binary_Stream_f)) {
+    Error(PERMISSION_ERROR_INPUT_TEXT_STREAM, ARG1, "peek/2");
+    return(FALSE);
+  }
+  if (status & Eof_Stream_f) {
+    Error(PERMISSION_ERROR_INPUT_PAST_END_OF_STREAM, ARG1, "peek/2");
+    return(FALSE);
+  }
+  s = Stream+sno;
+  ocharcount = s->charcount;
+  olinecount = s->linecount;
+  olinepos = s->linepos;
+  ch = Stream[sno].stream_getc(sno);
+  s->charcount = ocharcount;
+  s->linecount = olinecount;
+  s->linepos = olinepos;
+  /* buffer the character */
+  s->och = ch;
+  /* mark a special function to recover this character */
+  s->stream_getc = PlUnGetc;
+  if (CharConversionTable != NULL)
+    s->stream_getc_for_read = ISOGetc;
+  else
+    s->stream_getc_for_read = s->stream_getc;
+  return(unify_constant(ARG2,MkIntTerm(ch)));
+}
+
 static Int
 p_peek (void)
 {				/* at_end_of_stream */
@@ -4840,7 +4887,7 @@ InitIOPreds(void)
   InitCPred ("$file_name", 2, p_file_name, SafePredFlag|SyncPredFlag),
   InitCPred ("$past_eof", 1, p_past_eof, SafePredFlag|SyncPredFlag),
   InitCPred ("$peek", 2, p_peek, SafePredFlag|SyncPredFlag),
-  InitCPred ("$peek_byte", 2, p_peek, SafePredFlag|SyncPredFlag),
+  InitCPred ("$peek_byte", 2, p_peek_byte, SafePredFlag|SyncPredFlag),
   InitCPred ("current_input", 1, p_current_input, SafePredFlag|SyncPredFlag);
   InitCPred ("current_output", 1, p_current_output, SafePredFlag|SyncPredFlag);
   InitCPred ("prompt", 1, p_setprompt, SafePredFlag|SyncPredFlag);
diff --git a/pl/preds.yap b/pl/preds.yap
index efce73016..f781be451 100644
--- a/pl/preds.yap
+++ b/pl/preds.yap
@@ -436,9 +436,17 @@ abolish(X) :-
 	throw(error(type_error(atom,M), Msg)).
 
 '$old_abolish'(V,M) :- var(V), !,
-	'$abolish_all_old'(M).
+	( '$access_yap_flags'(8, 1) ->
+	    throw(error(instantiation_error,abolish(M:V)))
+	;
+	    '$abolish_all_old'(M)
+	).
 '$old_abolish'(A,M) :- atom(A), !,
-	'$abolish_all_atoms_old'(A,M).
+	( '$access_yap_flags'(8, 1) ->
+	  throw(error(type_error(predicate_indicator,A),abolish(M:A)))
+	;
+	    '$abolish_all_atoms_old'(A,M)
+	).
 '$old_abolish'(M:N,_) :- !,
 	'$old_abolish'(N,M).
 '$old_abolish'([], _) :- !.
diff --git a/pl/utils.yap b/pl/utils.yap
index 9dae719d5..e70cdcfec 100644
--- a/pl/utils.yap
+++ b/pl/utils.yap
@@ -338,10 +338,10 @@ current_predicate(M:F) :-			% module specified
 current_predicate(M:F) :- % module specified
 	!,
 	'$current_predicate3'(M,F).
-current_predicate(F) :-			% only for the predicate
+current_predicate(S) :-			% only for the predicate
 	'$current_module'(M),
-	'$current_predicate3'(M,F).
-
+	'$current_predicate3'(M,S).
+	
 system_predicate(A,P) :-
 	'$current_predicate_no_modules'(prolog,A,P),
 	\+ '$hidden'(A).
@@ -356,11 +356,13 @@ system_predicate(P) :-
 	functor(T,A,Arity),
 	'$pred_exists'(T,M).
 
-'$current_predicate3'(M,A/Arity) :-
+'$current_predicate3'(M,A/Arity) :- !,
 	'$current_predicate'(M,A,Arity),
 	\+ '$hidden'(A),
 	functor(T,A,Arity),
 	'$pred_exists'(T,M).
+'$current_predicate3'(M,BadSpec) :-			% only for the predicate
+	throw(error(type_error(predicate_indicator,BadSpec),current_predicate(M:BadSpec))).
 
 %%% User interface for statistics
 
diff --git a/pl/yio.yap b/pl/yio.yap
index 904ce7d5b..b4c162aaf 100644
--- a/pl/yio.yap
+++ b/pl/yio.yap
@@ -664,7 +664,6 @@ put(Stream,N) :-  N1 is N, '$put'(Stream,N1).
 
 skip(N) :- current_input(S),  N1 is N, '$skip'(S,N1).
 
-skip(Stream,_) :- \+ '$check_stream'(Stream,read), !, fail.
 skip(Stream,N) :- N1 is N, '$skip'(Stream,N1).
 
 '$tab'(N) :- N<1, !.
@@ -774,7 +773,6 @@ stream_property(Stream, Props) :-  var(Stream), !,
 	'$current_stream'(_,_,Stream),
 	'$stream_property'(Stream, Props).
 stream_property(Stream, Props) :-
-	'$check_stream'(Stream), !,
 	'$stream_property'(Stream, Props).
 stream_property(Stream, Props) :-
 	throw(error(domain_error(stream,Stream),stream_property(Stream, Props))).