diff --git a/include/isam.cpp b/include/isam.cpp
index 1e6047343..af9f90875 100755
--- a/include/isam.cpp
+++ b/include/isam.cpp
@@ -2570,10 +2570,10 @@ int TSystemisamfile::overwrite(
   nitems = ftell(fl);
   fclose(fl);
 
-  err = _open_ex();
+  err = _open_ex(_excllock);
   if (err != NOERR)
   {
-    error_box("Impossibile aprire il file %d", _logicnum);
+    error_box("Impossibile aprire il file %d in modo esclusivo", _logicnum);
     return err;
   }
   
diff --git a/include/mask.cpp b/include/mask.cpp
index 76a1d131e..9d223a676 100755
--- a/include/mask.cpp
+++ b/include/mask.cpp
@@ -1509,28 +1509,24 @@ const TString& TMask::get(const char * fld_id) const
 
 long TMask::get_long(short fld_id) const
 {
-//  const TString& s = field(fld_id).get();
   const TString& s = get(fld_id);
   return atol(s);
 }
 
 bool TMask::get_bool(short fld_id) const
 {
-//  const TString& s = field(fld_id).get();
   const TString& s = get(fld_id);
-  return s.not_empty();
+  return s.full() && s != "0";
 }
 
 real TMask::get_real(short fld_id) const
 {
-//  const TString& s = field(fld_id).get();
   const TString& s = get(fld_id);
   return real(s);
 }
 
 TDate TMask::get_date(short fld_id) const
 {
-//  const TString& s = field(fld_id).get();
   const TString& s = get(fld_id);
   return TDate(s);
 }
@@ -1544,7 +1540,7 @@ TCurrency& TMask::get_currency(short fld_id, TCurrency& c) const
   }
   else
   {           
-    real n(cf.get());
+    const real n(cf.get());
     c.force_value("");
     c.set_num(n);
   }