diff --git a/src/gsi/gsi/gsiClassBase.cc b/src/gsi/gsi/gsiClassBase.cc
index e6548ef8f..491a03186 100644
--- a/src/gsi/gsi/gsiClassBase.cc
+++ b/src/gsi/gsi/gsiClassBase.cc
@@ -390,6 +390,30 @@ sm_assign (const char *name, const gsi::ClassBase *cls)
   return sm;
 }
 
+static const std::set<std::pair<std::string, bool> > &name_map_for_class (const gsi::ClassBase *cls, std::map<const gsi::ClassBase *, std::set<std::pair<std::string, bool> > > &cache)
+{
+  if (! cls) {
+    static std::set<std::pair<std::string, bool> > empty;
+    return empty;
+  }
+
+  std::map<const gsi::ClassBase *, std::set<std::pair<std::string, bool> > >::iterator cc = cache.find (cls);
+  if (cc != cache.end ()) {
+    return cc->second;
+  }
+
+  cc = cache.insert (std::make_pair ((const gsi::ClassBase *) 0, std::set<std::pair<std::string, bool> > ())).first;
+  cc->second = name_map_for_class (cls->base (), cache);
+
+  for (gsi::ClassBase::method_iterator m = cls->begin_methods (); m != cls->end_methods (); ++m) {
+    for (gsi::MethodBase::synonym_iterator syn = (*m)->begin_synonyms (); syn != (*m)->end_synonyms (); ++syn) {
+      cc->second.insert (std::make_pair (syn->name, (*m)->is_static ()));
+    }
+  }
+
+  return cc->second;
+}
+
 void
 ClassBase::merge_declarations ()
 {
@@ -433,6 +457,8 @@ ClassBase::merge_declarations ()
     }
   }
 
+  std::map<const gsi::ClassBase *, std::set<std::pair<std::string, bool> > > name_maps;
+
   //  Add to the classes the special methods and clean up the method table
   for (gsi::ClassBase::class_iterator c = gsi::ClassBase::begin_new_classes (); c != gsi::ClassBase::end_new_classes (); ++c) {
 
@@ -441,12 +467,7 @@ ClassBase::merge_declarations ()
       continue;
     }
 
-    std::set<std::pair<std::string, bool> > name_map;
-    for (gsi::ClassBase::method_iterator m = c->begin_methods (); m != c->end_methods (); ++m) {
-      for (gsi::MethodBase::synonym_iterator syn = (*m)->begin_synonyms (); syn != (*m)->end_synonyms (); ++syn) {
-        name_map.insert (std::make_pair (syn->name, (*m)->is_static ()));
-      }
-    }
+    const std::set<std::pair<std::string, bool> > &name_map = name_map_for_class (c.operator-> (), name_maps);
 
     //  We don't want the declaration object to be non-const except for this case. So
     //  we const_cast here.
diff --git a/src/lay/lay/layMainWindow.cc b/src/lay/lay/layMainWindow.cc
index 43e81307e..c308eeeb4 100644
--- a/src/lay/lay/layMainWindow.cc
+++ b/src/lay/lay/layMainWindow.cc
@@ -689,6 +689,14 @@ MainWindow::MainWindow (QApplication *app, lay::Plugin *plugin_parent, const cha
 
 MainWindow::~MainWindow ()
 {
+  //  avoid deferred execution later on where there isn't a valid main window anymore
+  //  (problem case: showing a dialog inside main windows's destroyed signal - this will
+  //  process events and trigger execution if not disabled)
+  if (! tl::DeferredMethodScheduler::instance ()->is_disabled ()) {
+    tl::DeferredMethodScheduler::instance ()->execute ();
+  }
+  tl::DeferredMethodScheduler::instance ()->enable (false);
+
   lay::register_help_handler (0, 0);
 
   //  since the configuration actions unregister themselves, we need to do this before the main
diff --git a/src/rba/rba/rbaUtils.h b/src/rba/rba/rbaUtils.h
index 81fd2bc75..7c1cfa30e 100644
--- a/src/rba/rba/rbaUtils.h
+++ b/src/rba/rba/rbaUtils.h
@@ -180,12 +180,12 @@ inline void rb_protect_init ()
 
 #define RUBY_BEGIN_EXEC \
   try { \
-    rba::RubyInterpreter::instance()->begin_exec ();
+    if (rba::RubyInterpreter::instance ()) { rba::RubyInterpreter::instance ()->begin_exec (); }
 
 #define RUBY_END_EXEC \
-    rba::RubyInterpreter::instance()->end_exec (); \
+    if (rba::RubyInterpreter::instance ()) { rba::RubyInterpreter::instance()->end_exec (); } \
   } catch (...) { \
-    rba::RubyInterpreter::instance()->end_exec (); \
+    if (rba::RubyInterpreter::instance ()) { rba::RubyInterpreter::instance()->end_exec (); } \
     throw; \
   }