diff --git a/indra/newview/llviewerobject.cpp b/indra/newview/llviewerobject.cpp
index 49745fd16..2da884354 100644
--- a/indra/newview/llviewerobject.cpp
+++ b/indra/newview/llviewerobject.cpp
@@ -205,7 +205,6 @@ LLViewerObject::LLViewerObject(const LLUUID &id, const LLPCode pcode, LLViewerRe
 	mID(id),
 	mLocalID(0),
 	mTotalCRC(0),
-	mListIndex(-1),
 	mTEImages(NULL),
 	mGLName(0),
 	mbCanSelect(TRUE),
diff --git a/indra/newview/llviewerobject.h b/indra/newview/llviewerobject.h
index af369ba05..c849c458d 100644
--- a/indra/newview/llviewerobject.h
+++ b/indra/newview/llviewerobject.h
@@ -233,8 +233,6 @@ public:
 	const LLUUID &getID() const						{ return mID; }
 	U32 getLocalID() const							{ return mLocalID; }
 	U32 getCRC() const								{ return mTotalCRC; }
-	S32 getListIndex() const						{ return mListIndex; }
-	void setListIndex(S32 idx)						{ mListIndex = idx; }
 
 	virtual BOOL isFlexible() const					{ return FALSE; }
 	virtual BOOL isSculpted() const 				{ return FALSE; }
@@ -618,9 +616,6 @@ public:
 	// Last total CRC received from sim, used for caching
 	U32				mTotalCRC;
 
-	// index into LLViewerObjectList::mActiveObjects or -1 if not in list
-	S32				mListIndex;
-
 	LLPointer<LLViewerTexture> *mTEImages;
 
 	// Selection, picking and rendering variables
diff --git a/indra/newview/llviewerobjectlist.cpp b/indra/newview/llviewerobjectlist.cpp
index b1810eeed..475950f5d 100644
--- a/indra/newview/llviewerobjectlist.cpp
+++ b/indra/newview/llviewerobjectlist.cpp
@@ -918,30 +918,21 @@ void LLViewerObjectList::update(LLAgent &agent, LLWorld &world)
 	LLViewerObject *objectp = NULL;	
 	
 	// Make a copy of the list in case something in idleUpdate() messes with it
-	static std::vector<LLViewerObject*> idle_list;
-
-	U32 idle_count = 0;
-		
+	std::vector<LLViewerObject*> idle_list;
+	
 	static LLFastTimer::DeclareTimer idle_copy("Idle Copy");
 
 	{
 		LLFastTimer t(idle_copy);
-		
- 		for (std::vector<LLPointer<LLViewerObject> >::iterator active_iter = mActiveObjects.begin();
+		idle_list.reserve( mActiveObjects.size() );
+
+ 		for (std::set<LLPointer<LLViewerObject> >::iterator active_iter = mActiveObjects.begin();
 			active_iter != mActiveObjects.end(); active_iter++)
 		{
 			objectp = *active_iter;
 			if (objectp)
 			{
-				if (idle_count >= idle_list.size())
-				{
-					idle_list.push_back( objectp );
-				}
-				else
-				{
-					idle_list[idle_count] = objectp;
-				}
-				++idle_count;
+				idle_list.push_back( objectp );
 			}
 			else
 			{	// There shouldn't be any NULL pointers in the list, but they have caused
@@ -951,12 +942,11 @@ void LLViewerObjectList::update(LLAgent &agent, LLWorld &world)
 		}
 	}
 
-	std::vector<LLViewerObject*>::iterator idle_end = idle_list.begin()+idle_count;
 	static const LLCachedControl<bool> freeze_time("FreezeTime",0);
 	if (freeze_time)
 	{
 		for (std::vector<LLViewerObject*>::iterator iter = idle_list.begin();
-			iter != idle_end; iter++)
+			iter != idle_list.end(); iter++)
 		{
 			objectp = *iter;
 			if (
@@ -972,18 +962,18 @@ void LLViewerObjectList::update(LLAgent &agent, LLWorld &world)
 	else
 	{
 		for (std::vector<LLViewerObject*>::iterator idle_iter = idle_list.begin();
-			idle_iter != idle_end; idle_iter++)
+			idle_iter != idle_list.end(); idle_iter++)
 		{
 			objectp = *idle_iter;
-			if (objectp->idleUpdate(agent, world, frame_time))
-			{
-				num_active_objects++;				
-			}
-			else
+			if (!objectp->idleUpdate(agent, world, frame_time))
 			{
 				//  If Idle Update returns false, kill object!
 				kill_list.push_back(objectp);
 			}
+			else
+			{
+				num_active_objects++;
+			}
 		}
 		for (std::vector<LLViewerObject*>::iterator kill_iter = kill_list.begin();
 			kill_iter != kill_list.end(); kill_iter++)
@@ -1225,7 +1215,7 @@ void LLViewerObjectList::cleanupReferences(LLViewerObject *objectp)
 	{
 		//llinfos << "Removing " << objectp->mID << " " << objectp->getPCodeString() << " from active list in cleanupReferences." << llendl;
 		objectp->setOnActiveList(FALSE);
-		removeFromActiveList(objectp);
+		mActiveObjects.erase(objectp);
 	}
 
 	if (objectp->isOnMap())
@@ -1292,7 +1282,6 @@ BOOL LLViewerObjectList::killObject(LLViewerObject *objectp)
 
 		return TRUE;
 	}
-
 	return FALSE;
 }
 
@@ -1416,26 +1405,6 @@ void LLViewerObjectList::cleanDeadObjects(BOOL use_timer)
 	mNumDeadObjects = 0;
 }
 
-void LLViewerObjectList::removeFromActiveList(LLViewerObject* objectp)
-{
-	S32 idx = objectp->getListIndex();
-	if (idx != -1)
-	{ //remove by moving last element to this object's position
-		llassert(mActiveObjects[idx] == objectp);
-		
-		objectp->setListIndex(-1);
-
-		S32 last_index = mActiveObjects.size()-1;
-
-		if (idx != last_index)
-		{
-			mActiveObjects[idx] = mActiveObjects[last_index];
-			mActiveObjects[idx]->setListIndex(idx);
-			mActiveObjects.pop_back();
-		}
-	}
-}
-
 void LLViewerObjectList::updateActive(LLViewerObject *objectp)
 {
 	LLMemType mt(LLMemType::MTYPE_OBJECT);
@@ -1450,29 +1419,13 @@ void LLViewerObjectList::updateActive(LLViewerObject *objectp)
 		if (active)
 		{
 			//llinfos << "Adding " << objectp->mID << " " << objectp->getPCodeString() << " to active list." << llendl;
-			S32 idx = objectp->getListIndex();
-			if (idx <= -1)
-			{
-				mActiveObjects.push_back(objectp);
-				objectp->setListIndex(mActiveObjects.size()-1);
-				objectp->setOnActiveList(TRUE);
-			}
-			else
-			{
-				llassert(idx < (S32)mActiveObjects.size());
-				llassert(mActiveObjects[idx] == objectp);
-
-				if (idx >= (S32)mActiveObjects.size() ||
-					mActiveObjects[idx] != objectp)
-				{
-					llwarns << "Invalid object list index detected!" << llendl;
-				}
-			}
+			mActiveObjects.insert(objectp);
+			objectp->setOnActiveList(TRUE);
 		}
 		else
 		{
 			//llinfos << "Removing " << objectp->mID << " " << objectp->getPCodeString() << " from active list." << llendl;
-			removeFromActiveList(objectp);
+			mActiveObjects.erase(objectp);
 			objectp->setOnActiveList(FALSE);
 		}
 	}
diff --git a/indra/newview/llviewerobjectlist.h b/indra/newview/llviewerobjectlist.h
index 5a48656b7..9266dcf2d 100644
--- a/indra/newview/llviewerobjectlist.h
+++ b/indra/newview/llviewerobjectlist.h
@@ -128,9 +128,7 @@ public:
 
 	void dirtyAllObjectInventory();
 
-	void removeFromActiveList(LLViewerObject* objectp);
 	void updateActive(LLViewerObject *objectp);
-	
 	void updateAvatarVisibility();
 
 	// Selection related stuff
@@ -208,7 +206,7 @@ public:
 	typedef std::vector<LLPointer<LLViewerObject> > vobj_list_t;
 
 	vobj_list_t mObjects;
-	std::vector<LLPointer<LLViewerObject> > mActiveObjects;
+	std::set<LLPointer<LLViewerObject> > mActiveObjects;
 
 	vobj_list_t mMapObjects;