diff --git a/src/Buffer.cpp b/src/Buffer.cpp
index 0badaae88c..8abdcc8632 100644
--- a/src/Buffer.cpp
+++ b/src/Buffer.cpp
@@ -139,13 +139,13 @@ void showPrintError(string const & name)
 	Alert::error(_("Print document failed"), str);
 }
 
-/// a list of Buffers we cloned
-set<Buffer *> cloned_buffer_list;
-
-
 } // namespace anon
 
 
+// A storehouse for the cloned buffers.
+list<CloneList> cloned_buffers;
+
+
 class Buffer::Impl
 {
 public:
@@ -305,6 +305,8 @@ public:
 	/// If non zero, this buffer is a clone of existing buffer \p cloned_buffer_
 	/// This one is useful for preview detached in a thread.
 	Buffer const * cloned_buffer_;
+	///
+	CloneList * clone_list_;
 	/// are we in the process of exporting this buffer?
 	mutable bool doing_export;
 	
@@ -341,7 +343,7 @@ Buffer::Impl::Impl(Buffer * owner, FileName const & file, bool readonly_,
 	  toc_backend(owner), macro_lock(false), timestamp_(0), checksum_(0),
 	  wa_(0), gui_(0), undo_(*owner), bibinfo_cache_valid_(false), 
 	  bibfile_cache_valid_(false), cite_labels_valid_(false), 
-	  preview_loader_(0), cloned_buffer_(cloned_buffer),
+	  preview_loader_(0), cloned_buffer_(cloned_buffer), clone_list_(0),
 	  doing_export(false), parent_buffer(0)
 {
 	if (!cloned_buffer_) {
@@ -402,13 +404,13 @@ Buffer::~Buffer()
 	if (isClone()) {
 		// this is in case of recursive includes: we won't try to delete
 		// ourselves as a child.
-		cloned_buffer_list.erase(this);
+		d->clone_list_->erase(this);
 		// loop over children
 		Impl::BufferPositionMap::iterator it = d->children_positions.begin();
 		Impl::BufferPositionMap::iterator end = d->children_positions.end();
 		for (; it != end; ++it) {
 			Buffer * child = const_cast<Buffer *>(it->first);
-				if (cloned_buffer_list.erase(child))
+				if (d->clone_list_->erase(child))
 					delete child;
 		}
 		// FIXME Do we really need to do this right before we delete d?
@@ -451,28 +453,21 @@ Buffer::~Buffer()
 Buffer * Buffer::clone() const
 {
 	BufferMap bufmap;
-	masterBuffer()->clone(bufmap);
+	cloned_buffers.push_back(CloneList());
+	CloneList * clones = &cloned_buffers.back();
+
+	masterBuffer()->clone(bufmap, clones);
 
 	// make sure we got cloned
 	BufferMap::const_iterator bit = bufmap.find(this);
 	LASSERT(bit != bufmap.end(), return 0);
 	Buffer * cloned_buffer = bit->second;
 
-	// this should be empty. if not, then either we have left
-	// some buffer undeleted, or else we are trying to export
-	// two buffers at once. either way is a problem.
-	LASSERT(cloned_buffer_list.empty(), return 0);
-	// record the list of cloned buffers in the cloned master
-	BufferMap::iterator it = bufmap.begin();
-	BufferMap::iterator en = bufmap.end();
-	for (; it != en; ++it)
-		cloned_buffer_list.insert(it->second);
-
 	return cloned_buffer;
 }
 
 
-void Buffer::clone(BufferMap & bufmap) const
+void Buffer::clone(BufferMap & bufmap, CloneList * clones) const
 {
 	// have we already been cloned?
 	if (bufmap.find(this) != bufmap.end())
@@ -480,6 +475,8 @@ void Buffer::clone(BufferMap & bufmap) const
 
 	Buffer * buffer_clone = new Buffer(fileName().absFileName(), false, this);
 	bufmap[this] = buffer_clone;
+	clones->insert(buffer_clone);
+	buffer_clone->d->clone_list_ = clones;
 	buffer_clone->d->macro_lock = true;
 	buffer_clone->d->children_positions.clear();
 	// FIXME (Abdel 09/01/2010): this is too complicated. The whole children_positions and
@@ -493,7 +490,7 @@ void Buffer::clone(BufferMap & bufmap) const
 		dit.setBuffer(buffer_clone);
 		Buffer * child = const_cast<Buffer *>(it->second.second);
 
-		child->clone(bufmap);
+		child->clone(bufmap, clones);
 		BufferMap::iterator const bit = bufmap.find(child);
 		LASSERT(bit != bufmap.end(), continue);
 		Buffer * child_clone = bit->second;
diff --git a/src/Buffer.h b/src/Buffer.h
index bf2a9ead6b..0c15c0e2d2 100644
--- a/src/Buffer.h
+++ b/src/Buffer.h
@@ -79,6 +79,8 @@ class PreviewLoader;
 
 class Buffer;
 typedef std::list<Buffer *> ListOfBuffers;
+/// a list of Buffers we cloned
+typedef std::set<Buffer *> CloneList;
 
 
 /** The buffer object.
@@ -230,7 +232,7 @@ private:
 	///
 	typedef std::map<Buffer const *, Buffer *> BufferMap;
 	///
-	void clone(BufferMap &) const;
+	void clone(BufferMap &, CloneList *) const;
 	/// save timestamp and checksum of the given file.
 	void saveCheckSum() const;	
 	/// read a new file