diff --git a/src/backend/concrete_simulation.cc b/src/backend/concrete_simulation.cc
index f9a22c5..4285682 100644
--- a/src/backend/concrete_simulation.cc
+++ b/src/backend/concrete_simulation.cc
@@ -19,6 +19,7 @@
 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 
 #include "concrete_simulation.hh"
+
 #include <sgpemv2/simulation_observer.hh>
 #include <sgpemv2/scheduler.hh>
 #include <sgpemv2/cpu_policies_gatekeeper.hh>
@@ -61,7 +62,7 @@ ConcreteSimulation::jump_to(History::position p) throw(UserInterruptException, N
   switch (_state)
   {
   case state_running:
-    // pauses the simulation (see below)
+    // pauses the simulation (done below)
  		break;
   case state_stopped:
     _history.set_front(0);
@@ -72,7 +73,6 @@ ConcreteSimulation::jump_to(History::position p) throw(UserInterruptException, N
 
   // Disable momentarily updates for registered observers on 
   // sgpem::Simulation too.
-  // See History for an example of how to implement this.
   set_notify_enabled(false);
 	pause();
 
@@ -83,8 +83,16 @@ ConcreteSimulation::jump_to(History::position p) throw(UserInterruptException, N
   History::position increment = 0;
 	while (yet_to_finish && p > _history.get_front() + increment)
   {
-		yet_to_finish = step();
-    increment++;
+    try
+      {
+        yet_to_finish = step();
+        increment++;
+      }
+    catch(...)
+      {
+        // FIXME: manage exceptions! Lookout that notifications
+        // have to be re-enabled.
+      }
   }
   get_history().set_front(std::min(p, _history.get_size()));
 	if (!yet_to_finish)
diff --git a/src/jump_to_dialog.cc b/src/jump_to_dialog.cc
index 15d855d..dcd5802 100644
--- a/src/jump_to_dialog.cc
+++ b/src/jump_to_dialog.cc
@@ -18,17 +18,21 @@
 // along with SGPEMv2; if not, write to the Free Software
 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 
+#include "gettext.h"
+
 #include "jump_to_dialog.hh"
+
 #include <sgpemv2/templates/sequences.tcc>
 #include <sgpemv2/history.hh>
 #include <sgpemv2/environment.hh>
 #include <sgpemv2/simulation.hh>
 #include <sgpemv2/resource.hh>
 
-#include <iostream>
-#include <sstream>
+#include <gtkmm/main.h>
 
-#include "gettext.h"
+#ifndef NDEBUG
+#include <iostream>
+#endif
 
 #include <cassert>
 
@@ -56,6 +60,11 @@ JumpToDialog::JumpToDialog(BaseObjectType* cobject, const RefPtr<Xml>& glade) :
   _stop_button->signal_clicked().connect(
       sigc::mem_fun(*this, &JumpToDialog::_on_stop));
 
+  _ok_button->signal_clicked().connect(sigc::bind(
+      sigc::mem_fun(*this, &JumpToDialog::response), RESPONSE_OK));
+  _ok_button->signal_clicked().connect(
+      sigc::mem_fun(*this, &JumpToDialog::hide));
+
   // FIXME: not implemented
   _stop_button->set_sensitive(false);
 }
@@ -64,24 +73,47 @@ void
 JumpToDialog::_on_jump()
 {
   _ok_button->set_sensitive(false);
-//  _stop_button->set_sensitive(true);
+  _stop_button->set_sensitive(true);
   _jump_button->set_sensitive(false);
   _progress->set_fraction(0.0);
   
+  assert(_instant_spin->get_value_as_int() > 0);
   _target_instant = _instant_spin->get_value_as_int();
 
-  Simulation::get_instance().attach(*this);
-  Simulation::get_instance().jump_to(_target_instant);
-  Simulation::get_instance().detach(*this);
+  Simulation& sim = Simulation::get_instance();
+  History&    h   = sim.get_history();
+
+  sim.attach(*this);
+  h.set_notify_enabled(false);
+  try
+    {
+    if(_target_instant < h.get_size() - 1)
+      sim.jump_to(_target_instant);
+    else
+      sim.jump_to(h.get_size() - 1);
+      while(h.get_front() < _target_instant)
+        {
+          sim.run();
+          if(sim.get_state() == Simulation::state_stopped)
+            break; // Simulation ended before reaching _target_instant
+        }
+    }
+  catch(...)
+    {
+    // FIXME: correctly manage exceptions!
+    }
+  h.set_notify_enabled(true);
+  sim.detach(*this);
 
   _ok_button->set_sensitive(true);
-//  _stop_button->set_sensitive(false);
+  _stop_button->set_sensitive(false);
   _jump_button->set_sensitive(true);
 }
 
 void
 JumpToDialog::_on_stop()
 {
+  Simulation::get_instance().stop();
 }
 
 void
@@ -92,4 +124,10 @@ JumpToDialog::update(const Simulation& changed_simulation)
   double percent = static_cast<double>(front) / _target_instant;
 
   _progress->set_fraction(percent);
+
+  //  Needed to force display (else under
+  //  intensive computation it doesn't have
+  //  the time to flush all UI events):
+  while(Gtk::Main::events_pending())
+       Gtk::Main::iteration();
 }