Possible fix

ebean-api/src/main/java/io/ebean/bean/EntityBeanIntercept.java

@@ -360,7 +360,7 @@ public final class EntityBeanIntercept implements Serializable {
    * Return true if the entity should be updated.
    */
   public boolean isUpdate() {
-    return forceUpdate || state == STATE_LOADED;
+    return forceUpdate || state == STATE_LOADED || state == STATE_REFERENCE;
   }
 
   /**

ebean-test/src/test/java/org/tests/model/onetoone/TestOneToOneCascadeSave.java

@@ -34,7 +34,7 @@ public class TestOneToOneCascadeSave extends BaseTestCase {
   }
   
   @Test
-  public void test2() {
+  public void testSaveCascadeWithOneToOne() {
     OtoMasterVersion master = new OtoMasterVersion();
     master.setName("m1");
 
@@ -59,12 +59,12 @@ public class TestOneToOneCascadeSave extends BaseTestCase {
       master.setName("m2");
       DB.save(master);
       child = DB.find(OtoChildVersion.class).findOne();
-      // assertThat(child.getVersion()).isEqualTo(2); but is 1
+      assertThat(child.getVersion()).isEqualTo(2);
       child.setName("c3");
-      DB.save(child); // <-- throws OptimisticLockException
+      DB.save(child); 
       
       txn.commit();
     }
   }
-
+  
 }