diff --git a/src/java/com/threerings/presents/dobj/DObject.java b/src/java/com/threerings/presents/dobj/DObject.java
index 5e8144731..c86bdc455 100644
--- a/src/java/com/threerings/presents/dobj/DObject.java
+++ b/src/java/com/threerings/presents/dobj/DObject.java
@@ -866,8 +866,10 @@ public class DObject extends TrackedObject
         // if we're on the authoritative server, we update the set immediately
         DSet.Entry oldEntry = null;
         if (_omgr != null && _omgr.isManager(this)) {
-            oldEntry = set.get(key);
-            set.removeKey(key);
+            oldEntry = set.removeKey(key);
+            if (oldEntry == null) {
+                Thread.dumpStack();
+            }
         }
         // dispatch an entry removed event
         postEvent(new EntryRemovedEvent(_oid, name, key, oldEntry));
@@ -881,8 +883,10 @@ public class DObject extends TrackedObject
         // if we're on the authoritative server, we update the set immediately
         DSet.Entry oldEntry = null;
         if (_omgr != null && _omgr.isManager(this)) {
-            oldEntry = set.get(entry.getKey());
-            set.update(entry);
+            oldEntry = set.update(entry);
+            if (oldEntry == null) {
+                Thread.dumpStack();
+            }
         }
         // dispatch an entry updated event
         postEvent(new EntryUpdatedEvent(_oid, name, entry, oldEntry));
diff --git a/src/java/com/threerings/presents/dobj/DSet.java b/src/java/com/threerings/presents/dobj/DSet.java
index 17d546440..a15683c40 100644
--- a/src/java/com/threerings/presents/dobj/DSet.java
+++ b/src/java/com/threerings/presents/dobj/DSet.java
@@ -295,7 +295,7 @@ public class DSet
      */
     protected boolean remove (Entry elem)
     {
-        return removeKey(elem.getKey());
+        return (null != removeKey(elem.getKey()));
     }
 
     /**
@@ -304,10 +304,10 @@ public class DSet
      * <code>removeFrom{Set}()</code> method should be called on the
      * distributed object that contains the set in question.
      *
-     * @return true if a matching entry was removed, false if no entry
-     * in the set matched the key.
+     * @return the old matching entry if found and removed, null if not
+     * found.
      */
-    protected boolean removeKey (Object key)
+    protected Entry removeKey (Object key)
     {
         // look up this entry's position in our set
         int eidx = ArrayUtil.binarySearch(
@@ -316,13 +316,14 @@ public class DSet
         // if we found it, remove it
         if (eidx >= 0) {
             // shift the remaining elements down
+            Entry oldEntry = _entries[eidx];
             System.arraycopy(_entries, eidx+1, _entries, eidx, _size-eidx-1);
             _entries[--_size] = null;
             _modCount++;
-            return true;
+            return oldEntry;
 
         } else {
-            return false;
+            return null;
         }
     }
 
@@ -333,10 +334,10 @@ public class DSet
      * <code>update{Set}()</code> method should be called on the
      * distributed object that contains the set in question.
      *
-     * @return true if the entry was updated, false if it was not
-     * already in the set (in which case nothing is updated).
+     * @return the old entry that was replaced, or null if it was not
+     * found (in which case nothing is updated).
      */
-    protected boolean update (Entry elem)
+    protected Entry update (Entry elem)
     {
         // look up this entry's position in our set
         int eidx = ArrayUtil.binarySearch(
@@ -344,11 +345,12 @@ public class DSet
 
         // if we found it, update it
         if (eidx >= 0) {
+            Entry oldEntry = _entries[eidx];
             _entries[eidx] = elem;
             _modCount++;
-            return true;
+            return oldEntry;
         } else {
-            return false;
+            return null;
         }
     }
 
diff --git a/src/java/com/threerings/presents/dobj/EntryAddedEvent.java b/src/java/com/threerings/presents/dobj/EntryAddedEvent.java
index 6190cff49..26eed49d7 100644
--- a/src/java/com/threerings/presents/dobj/EntryAddedEvent.java
+++ b/src/java/com/threerings/presents/dobj/EntryAddedEvent.java
@@ -84,7 +84,10 @@ public class EntryAddedEvent extends NamedEvent
         throws ObjectAccessException
     {
         if (!_alreadyApplied) {
-            ((DSet)target.getAttribute(_name)).add(_entry);
+            boolean added = ((DSet)target.getAttribute(_name)).add(_entry);
+            if (!added) {
+                Log.warning("Duplicate entry found [event=" + this + "].");
+            }
         }
         return true;
     }
diff --git a/src/java/com/threerings/presents/dobj/EntryRemovedEvent.java b/src/java/com/threerings/presents/dobj/EntryRemovedEvent.java
index c735622f6..bb2466078 100644
--- a/src/java/com/threerings/presents/dobj/EntryRemovedEvent.java
+++ b/src/java/com/threerings/presents/dobj/EntryRemovedEvent.java
@@ -1,5 +1,5 @@
 //
-// $Id: EntryRemovedEvent.java,v 1.17 2004/08/27 02:20:20 mdb Exp $
+// $Id$
 //
 // Narya library - tools for developing networked games
 // Copyright (C) 2002-2004 Three Rings Design, Inc., All Rights Reserved
@@ -21,6 +21,8 @@
 
 package com.threerings.presents.dobj;
 
+import com.threerings.presents.Log;
+
 /**
  * An entry removed event is dispatched when an entry is removed from a
  * {@link DSet} attribute of a distributed object. It can also be
@@ -82,10 +84,14 @@ public class EntryRemovedEvent extends NamedEvent
     {
         if (_oldEntry == UNSET_OLD_ENTRY) {
             DSet set = (DSet)target.getAttribute(_name);
-            // fetch the previous value for interested callers
-            _oldEntry = set.get(_key);
-            // remove it from the set
-            set.removeKey(_key);
+            // remove, fetch the previous value for interested callers
+            _oldEntry = set.removeKey(_key);
+            if (_oldEntry == null) {
+                // complain if there was actually nothing there
+                Log.warning("No matching entry to remove [key=" + _key +
+                            ", set=" + set + "].");
+                return false;
+            }
         }
         return true;
     }
diff --git a/src/java/com/threerings/presents/dobj/EntryUpdatedEvent.java b/src/java/com/threerings/presents/dobj/EntryUpdatedEvent.java
index 401a76527..35f5561e7 100644
--- a/src/java/com/threerings/presents/dobj/EntryUpdatedEvent.java
+++ b/src/java/com/threerings/presents/dobj/EntryUpdatedEvent.java
@@ -1,5 +1,5 @@
 //
-// $Id: EntryUpdatedEvent.java,v 1.13 2004/08/27 02:20:20 mdb Exp $
+// $Id$
 //
 // Narya library - tools for developing networked games
 // Copyright (C) 2002-2004 Three Rings Design, Inc., All Rights Reserved
@@ -87,10 +87,8 @@ public class EntryUpdatedEvent extends NamedEvent
         if (_oldEntry == UNSET_OLD_ENTRY) {
             DSet set = (DSet)target.getAttribute(_name);
             // fetch the previous value for interested callers
-            _oldEntry = set.get(_entry.getKey());
-
-            // update the entry
-            if (!set.update(_entry)) {
+            _oldEntry = set.update(_entry);
+            if (_oldEntry == null) {
                 // complain if we didn't update anything
                 Log.warning("No matching entry to update [entry=" + this +
                             ", set=" + set + "].");