diff --git a/sources/editor/editorcommands.cpp b/sources/editor/editorcommands.cpp
index 65618d128..881785d96 100644
--- a/sources/editor/editorcommands.cpp
+++ b/sources/editor/editorcommands.cpp
@@ -47,16 +47,20 @@ DeletePartsCommand::~DeletePartsCommand() {
 
 /// Restaure les parties supprimees
 void DeletePartsCommand::undo() {
+	editor_scene -> blockSignals(true);
 	foreach(QGraphicsItem *qgi, deleted_parts) {
 		editor_scene -> addItem(qgi);
 	}
+	editor_scene -> blockSignals(false);
 }
 
 /// Supprime les parties
 void DeletePartsCommand::redo() {
+	editor_scene -> blockSignals(true);
 	foreach(QGraphicsItem *qgi, deleted_parts) {
 		editor_scene -> removeItem(qgi);
 	}
+	editor_scene -> blockSignals(false);
 }
 
 /*** CutPartsCommand ***/
@@ -90,7 +94,11 @@ PastePartsCommand::~PastePartsCommand() {
 /// annule le coller
 void PastePartsCommand::undo() {
 	// enleve les parties
-	foreach(QGraphicsItem *part, content_) editor_scene_ -> removeItem(part);
+	editor_scene_ -> blockSignals(true);
+	foreach(QGraphicsItem *part, content_) {
+		editor_scene_ -> removeItem(part);
+	}
+	editor_scene_ -> blockSignals(false);
 	if (uses_offset) {
 		editor_view_ -> offset_paste_count_    = old_offset_paste_count_;
 		editor_view_ -> start_top_left_corner_ = old_start_top_left_corner_;
@@ -103,7 +111,11 @@ void PastePartsCommand::redo() {
 	if (first_redo) first_redo = false;
 	else {
 		// pose les parties
-		foreach(QGraphicsItem *part, content_) editor_scene_ -> addItem(part);
+		editor_scene_ -> blockSignals(true);
+		foreach(QGraphicsItem *part, content_) {
+			editor_scene_ -> addItem(part);
+		}
+		editor_scene_ -> blockSignals(false);
 		if (uses_offset) {
 			editor_view_ -> offset_paste_count_    = new_offset_paste_count_;
 			editor_view_ -> start_top_left_corner_ = new_start_top_left_corner_;
diff --git a/sources/editor/elementscene.cpp b/sources/editor/elementscene.cpp
index 5726c3e54..03160b556 100644
--- a/sources/editor/elementscene.cpp
+++ b/sources/editor/elementscene.cpp
@@ -45,6 +45,7 @@ ElementScene::ElementScene(QETElementEditor *editor, QObject *parent) :
 	qgi_manager(this),
 	element_editor(editor)
 {
+	setItemIndexMethod(NoIndex);
 	current_polygon = NULL;
 	setGrid(1, 1);
 	initPasteArea();
@@ -391,7 +392,6 @@ void ElementScene::keyPressEvent(QKeyEvent *e) {
 			case Qt::Key_Down:  movement = QPointF(0.0, +movement_length); break;
 		}
 		if (!movement.isNull() && !focusItem()) {
-			qDebug() << "keyPressEvent: let's move by " << movement;
 			if (!moving_parts_) {
 				moving_parts_ = true;
 				fsi_pos = movement;
@@ -759,6 +759,7 @@ void ElementScene::paste() {
 */
 void ElementScene::slot_select(const ElementContent &content) {
 	blockSignals(true);
+	clearSelection();
 	foreach(QGraphicsItem *qgi, content) qgi -> setSelected(true);
 	blockSignals(false);
 	emit(selectionChanged());
@@ -775,7 +776,7 @@ void ElementScene::slot_selectAll() {
 	Deselectionne tout
 */
 void ElementScene::slot_deselectAll() {
-	clearSelection();
+	slot_select(ElementContent());
 }
 
 /**
diff --git a/sources/editor/elementview.cpp b/sources/editor/elementview.cpp
index 71c62caf2..a21a14dcd 100644
--- a/sources/editor/elementview.cpp
+++ b/sources/editor/elementview.cpp
@@ -28,6 +28,7 @@ ElementView::ElementView(ElementScene *scene, QWidget *parent) :
 	scene_(scene),
 	offset_paste_count_(0)
 {
+	setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
 	setInteractive(true);
 	setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
 	setResizeAnchor(QGraphicsView::AnchorUnderMouse);
diff --git a/sources/editor/qetelementeditor.cpp b/sources/editor/qetelementeditor.cpp
index 9398f9072..3cf9dc8c3 100644
--- a/sources/editor/qetelementeditor.cpp
+++ b/sources/editor/qetelementeditor.cpp
@@ -39,6 +39,13 @@
 #include "texteditor.h"
 #include "textfieldeditor.h"
 
+/*
+	Nombre maximum de primitives affichees par la "liste des parties"
+	Au-dela, un petit message est affiche, indiquant que ce nombre a ete depasse
+	et que la liste ne sera donc pas mise a jour.
+*/
+#define QET_MAX_PARTS_IN_ELEMENT_EDITOR_LIST 200
+
 /**
 	Constructeur
 	@param parent QWidget parent
@@ -1119,17 +1126,25 @@ void QETElementEditor::slot_createPartsList() {
 	parts_list -> blockSignals(true);
 	parts_list -> clear();
 	QList<QGraphicsItem *> qgis = ce_scene -> zItems(true);
-	for (int j = qgis.count() - 1 ; j >= 0 ; -- j) {
-		QGraphicsItem *qgi = qgis[j];
-		if (CustomElementPart *cep = dynamic_cast<CustomElementPart *>(qgi)) {
-			QString part_desc = cep -> name();
-			QListWidgetItem *qlwi = new QListWidgetItem(part_desc);
-			QVariant v;
-			v.setValue<QGraphicsItem *>(qgi);
-			qlwi -> setData(42, v);
-			parts_list -> addItem(qlwi);
-			qlwi -> setSelected(qgi -> isSelected());
+	
+	// on ne construit plus la liste a partir de 200 primitives
+	// c'est ingerable : la maj de la liste prend trop de temps et le resultat
+	// est inexploitable
+	if (qgis.count() <= QET_MAX_PARTS_IN_ELEMENT_EDITOR_LIST) {
+		for (int j = qgis.count() - 1 ; j >= 0 ; -- j) {
+			QGraphicsItem *qgi = qgis[j];
+			if (CustomElementPart *cep = dynamic_cast<CustomElementPart *>(qgi)) {
+				QString part_desc = cep -> name();
+				QListWidgetItem *qlwi = new QListWidgetItem(part_desc);
+				QVariant v;
+				v.setValue<QGraphicsItem *>(qgi);
+				qlwi -> setData(42, v);
+				parts_list -> addItem(qlwi);
+				qlwi -> setSelected(qgi -> isSelected());
+			}
 		}
+	} else {
+		parts_list -> addItem(new QListWidgetItem(tr("Trop de primitives, liste non g\351n\351r\351e.")));
 	}
 	parts_list -> blockSignals(false);
 }
@@ -1138,9 +1153,10 @@ void QETElementEditor::slot_createPartsList() {
 	Met a jour la selection dans la liste des parties
 */
 void QETElementEditor::slot_updatePartsList() {
-	if (parts_list -> count() != ce_scene -> items().count()) {
+	int items_count = ce_scene -> items().count();
+	if (parts_list -> count() != items_count) {
 		slot_createPartsList();
-	} else {
+	} else if (items_count <= QET_MAX_PARTS_IN_ELEMENT_EDITOR_LIST) {
 		parts_list -> blockSignals(true);
 		int i = 0;
 		QList<QGraphicsItem *> items = ce_scene -> zItems(true);