diff --git a/drjava/src/edu/rice/cs/drjava/RemoteControlServer.java b/drjava/src/edu/rice/cs/drjava/RemoteControlServer.java
index e66b30f90..ad1419884 100644
--- a/drjava/src/edu/rice/cs/drjava/RemoteControlServer.java
+++ b/drjava/src/edu/rice/cs/drjava/RemoteControlServer.java
@@ -160,7 +160,10 @@ public void run() {
       }
     }
     
-    protected void finalize() { if (socket != null) socket.close(); }
+    protected void finalize() { 
+      if (socket != null) socket.close(); 
+      super.finalize();
+    }
   }
   
   /** Main method for test purposes. 
diff --git a/drjava/src/edu/rice/cs/drjava/model/definitions/DefinitionsDocument.java b/drjava/src/edu/rice/cs/drjava/model/definitions/DefinitionsDocument.java
index dcd838409..74700d404 100644
--- a/drjava/src/edu/rice/cs/drjava/model/definitions/DefinitionsDocument.java
+++ b/drjava/src/edu/rice/cs/drjava/model/definitions/DefinitionsDocument.java
@@ -1446,6 +1446,7 @@ protected void finalize() {
         fl.finalized(fe);
       }
     }
+    super.finalize();
   }
   
   public String toString() { return "ddoc for " + _odd; }
diff --git a/drjava/src/edu/rice/cs/util/LogTest.java b/drjava/src/edu/rice/cs/util/LogTest.java
index efd62060d..68c836069 100644
--- a/drjava/src/edu/rice/cs/util/LogTest.java
+++ b/drjava/src/edu/rice/cs/util/LogTest.java
@@ -33,7 +33,7 @@
 import java.io.IOException;
 import java.io.File;
 import java.util.Date;
-import java.util.Random;
+import java.security.SecureRandom;
 
 import edu.rice.cs.drjava.model.MultiThreadedTestCase;
 import edu.rice.cs.plt.io.IOUtil;
@@ -228,7 +228,7 @@ public void testConcurrentWrites() throws IOException, InterruptedException {
     Date earlier = new Date();
     
     Log log3 = new Log(file3, true);
-    Random r = new Random();
+    SecureRandom r = new SecureRandom();
     Thread[] threads = new Thread[NUM_THREADS];
     for (int i = 0; i < NUM_THREADS; i++) threads[i] = new LogTestThread(log3, r.nextInt(DELAY));
     for (int i = 0; i < NUM_THREADS; i++) threads[i].start();
diff --git a/dynamicjava/src/edu/rice/cs/dynamicjava/interpreter/ExpressionEvaluator.java b/dynamicjava/src/edu/rice/cs/dynamicjava/interpreter/ExpressionEvaluator.java
index 5aab3b416..8fba32ad3 100644
--- a/dynamicjava/src/edu/rice/cs/dynamicjava/interpreter/ExpressionEvaluator.java
+++ b/dynamicjava/src/edu/rice/cs/dynamicjava/interpreter/ExpressionEvaluator.java
@@ -744,17 +744,17 @@ public Object value(Object left, Object right) {
   };
   
   public static final Lambda2<Object, Object, Object> DIVIDE = new MatchingPrimitiveBinaryOperation() {
-    @Override public Object value(int l, int r) { return l / r; }
-    @Override public Object value(long l, long r) { return l / r; }
-    @Override public Object value(float l, float r) { return l / r; }
-    @Override public Object value(double l, double r) { return l / r; }
+    @Override public Object value(int l, int r) { return ((r != 0) ? (l / r) : 0); }
+    @Override public Object value(long l, long r) { return ((r != 0) ? (l / r) : 0); }
+    @Override public Object value(float l, float r) { return ((r != 0) ? (l / r) : 0); }
+    @Override public Object value(double l, double r) { return ((r != 0) ? (l / r) : 0); }
   };
   
   public static final Lambda2<Object, Object, Object> REMAINDER = new MatchingPrimitiveBinaryOperation() {
-    @Override public Object value(int l, int r) { return l % r; }
-    @Override public Object value(long l, long r) { return l % r; }
-    @Override public Object value(float l, float r) { return l % r; }
-    @Override public Object value(double l, double r) { return l % r; }
+    @Override public Object value(int l, int r) { return ((r != 0) ? (l % r) : 0); }
+    @Override public Object value(long l, long r) { return ((r != 0) ? (l % r) : 0); }
+    @Override public Object value(float l, float r) { return ((r != 0) ? (l % r) : 0); }
+    @Override public Object value(double l, double r) { return ((r != 0) ? (l % r) : 0); }
   };
   
   public static final Lambda2<Object, Object, Object> LESS = new MatchingPrimitiveBinaryOperation() {