diff -u -r1.12 -r1.13
--- DetectorElementStore.java	14 Sep 2007 23:48:19 -0000	1.12
+++ DetectorElementStore.java	25 Mar 2009 00:24:14 -0000	1.13
@@ -21,20 +21,29 @@

     
     public boolean add(IDetectorElement de)
     {   

-    	// Add to the list using super, which will check for dups, etc.

+    	// Add to the list using super.

     	super.add(de);
     	    	

-    	// Check to see if the id is cacheable ...
-    	

+    	// Check to see if the id is cacheable...

     	IIdentifier id = de.getIdentifier(); 
 
     	// Is the id non-null?
     	if (id != null)
     	{

-    		// Is the id flagged as valid?

+    		// Is the id valid?

     		if (id.isValid())

-    		{
-    			// Cache this DE in the lookup map.

+    		{    		        		       		   
+    			// Check for existing.
+    		    if (cache.get(id.getValue()) != null)
+    		    {
+    		        throw new IllegalArgumentException(
+    		                "Attempting to add DetectorElement <" 
+    		                + de.getName() + ">, but an existing DetectorElement <" 
+    		                + cache.get(id.getValue()).getName() 
+    		                + "> has the same id <" + id.toHexString() + ">.");
+    		    }
+    		    
+    		    // Cache this DE in the lookup map.

     			cache.put(id.getValue(), de);
     		}
     	}

@@ -48,5 +57,11 @@

     	IDetectorElement lookup = cache.get(id.getValue());
     	if (lookup != null) match.add(lookup);
     	return match;

-    }                 

+    }      
+    
+    public void clear()
+    {
+        cache.clear();
+        super.clear();
+    }

 }

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