diff --git a/tools/cooja/java/se/sics/cooja/GUI.java b/tools/cooja/java/se/sics/cooja/GUI.java
index 5d18aa907..dd60a7a6c 100644
--- a/tools/cooja/java/se/sics/cooja/GUI.java
+++ b/tools/cooja/java/se/sics/cooja/GUI.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: GUI.java,v 1.137 2009/06/15 18:13:45 fros4943 Exp $
+ * $Id: GUI.java,v 1.138 2009/06/24 07:56:15 fros4943 Exp $
  */
 
 package se.sics.cooja;
@@ -2222,9 +2222,8 @@ public class GUI extends Observable {
           try {
             shouldRetry = false;
             myGUI.doRemoveSimulation(false);
-            Simulation newSim = loadSimulationConfig(root, true);
+            Simulation newSim = loadSimulationConfig(root, true, new Long(randomSeed));
             myGUI.setSimulation(newSim, false);
-            myGUI.getSimulation().setRandomSeed(randomSeed);
 
             if (autoStart) {
               newSim.startSimulation();
@@ -3064,7 +3063,7 @@ public class GUI extends Observable {
       Document doc = builder.build(file);
       Element root = doc.getRootElement();
 
-      return loadSimulationConfig(root, quick);
+      return loadSimulationConfig(root, quick, null);
     } catch (JDOMException e) {
       logger.fatal("Config not wellformed: " + e.getMessage());
       return null;
@@ -3081,7 +3080,7 @@ public class GUI extends Observable {
       Document doc = builder.build(stringReader);
       Element root = doc.getRootElement();
 
-      return loadSimulationConfig(root, quick);
+      return loadSimulationConfig(root, quick, null);
     } catch (JDOMException e) {
       throw (SimulationCreationException) new SimulationCreationException(
           "Configuration file not wellformed: " + e.getMessage()).initCause(e);
@@ -3091,7 +3090,7 @@ public class GUI extends Observable {
     }
   }
 
-  private Simulation loadSimulationConfig(Element root, boolean quick)
+  private Simulation loadSimulationConfig(Element root, boolean quick, Long manualRandomSeed)
   throws SimulationCreationException {
     Simulation newSim = null;
 
@@ -3153,7 +3152,7 @@ public class GUI extends Observable {
           Collection<Element> config = ((Element) element).getChildren();
           newSim = new Simulation(this);
           System.gc();
-          boolean createdOK = newSim.setConfigXML(config, !quick);
+          boolean createdOK = newSim.setConfigXML(config, !quick, manualRandomSeed);
           if (!createdOK) {
             logger.info("Simulation not loaded");
             return null;
diff --git a/tools/cooja/java/se/sics/cooja/Simulation.java b/tools/cooja/java/se/sics/cooja/Simulation.java
index ad6f77690..0916053ce 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 1.47 2009/05/26 14:15:41 fros4943 Exp $
+ * $Id: Simulation.java,v 1.48 2009/06/24 07:56:15 fros4943 Exp $
  */
 
 package se.sics.cooja;
@@ -278,7 +278,7 @@ public class Simulation extends Observable implements Runnable {
   }
 
   /**
-   * Creates a new simulation with a delay time of 100 ms.
+   * Creates a new simulation
    */
   public Simulation(GUI gui) {
     myGUI = gui;
@@ -348,6 +348,13 @@ public class Simulation extends Observable implements Runnable {
     return randomSeed;
   }
 
+  /**
+   * @return Random seed (converted to a string)
+   */
+  public String getRandomSeedString() {
+    return Long.toString(randomSeed);
+  }
+
   /**
    * @param randomSeed Random seed
    */
@@ -462,20 +469,16 @@ public class Simulation extends Observable implements Runnable {
   }
 
   /**
-   * Sets the current simulation config depending on the given XML elements.
-   *
-   * @see #getConfigXML()
-   * @param configXML
-   *          Config XML elements
-   * @param visAvailable
-   *          True if simulation is allowed to show visualizers while loading
-   *          the given config
-   * @return True if simulation config set successfully
-   * @throws Exception
-   *           If configuration could not be loaded
+   * Sets the current simulation config depending on the given configuration.
+   * 
+   * @param configXML Simulation configuration
+   * @param visAvailable True if simulation is allowed to show visualizers
+   * @param manualRandomSeed Simulation random seed. May be null, in which case the configuration is used
+   * @return True if simulation was configured successfully
+   * @throws Exception If configuration could not be loaded
    */
   public boolean setConfigXML(Collection<Element> configXML,
-      boolean visAvailable) throws Exception {
+      boolean visAvailable, Long manualRandomSeed) throws Exception {
 
     // Parse elements
     for (Element element : configXML) {
@@ -492,7 +495,9 @@ public class Simulation extends Observable implements Runnable {
 
       // Random seed
       if (element.getName().equals("randomseed")) {
-        if (element.getText().equals("generated")) {
+        if (manualRandomSeed != null) {
+          setRandomSeed(manualRandomSeed);
+        } else if (element.getText().equals("generated")) {
           randomSeedGenerated = true;
           setRandomSeed(new Random().nextLong());
         } else {