diff --git a/tools/cooja/java/se/sics/cooja/Simulation.java b/tools/cooja/java/se/sics/cooja/Simulation.java
index 1c7cebbc6..b13ebe95d 100644
--- a/tools/cooja/java/se/sics/cooja/Simulation.java
+++ b/tools/cooja/java/se/sics/cooja/Simulation.java
@@ -24,7 +24,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $Id: Simulation.java,v 1.24 2008/09/29 23:04:27 fros4943 Exp $
+ * $Id: Simulation.java,v 1.25 2008/10/03 09:37:01 fros4943 Exp $
  */
 
 package se.sics.cooja;
@@ -207,16 +207,14 @@ public class Simulation extends Observable implements Runnable {
         }
 
         if (stopSimulation) {
-          // We should only tick once (and we just did), so abort now
-          stopSimulation = false;
           isRunning = false;
-          thread = null;
         }
 
-
     }
     } catch (InterruptedException e) {
-      logger.warn("InterruptedException:" + e);
+      if (isRunning) {
+        logger.warn("InterruptedException:" + e);
+      }
     } catch (IllegalArgumentException e) {
       logger.warn("llegalArgumentException:" + e);
     } catch (IllegalMonitorStateException e) {