diff --git a/univention-management-console-module-appcenter-selfservice/umc/js/appcenter-selfservice/ThumbnailBox.js b/univention-management-console-module-appcenter-selfservice/umc/js/appcenter-selfservice/ThumbnailBox.js
index 4a68455..a8e97a1 100644
--- a/univention-management-console-module-appcenter-selfservice/umc/js/appcenter-selfservice/ThumbnailBox.js
+++ b/univention-management-console-module-appcenter-selfservice/umc/js/appcenter-selfservice/ThumbnailBox.js
@@ -139,9 +139,11 @@ define([
 				'class': 'thumbnailBoxImageInput',
 				buttonLabel: this._uploadImageButtonLabel,
 				showClearButton: false,
+				maxSize: 1 * 1024 * 1024,
 				updateView: lang.hitch(this, '_updateUploadedImagePreview')
 			});
 			this._imageUploader.startup();
+			this._imageUploader.watch('value', lang.hitch(this, '_updateValue'));
 
 			this._youtubeVideoTextBox = new TextBox({
 				'class': 'thumbnailBoxYoutubeInput',
@@ -152,6 +154,12 @@ define([
 			this._youtubeVideoTextBox.on('keypress', lang.hitch(this, 'checkForEnterPress'));
 		},
 
+		_updateValue: function() {
+			function _cut(val) { if (typeof val == 'string') {return val.substr(0, 20) + '...';} return val; }
+			console.log('### ThumbnailBox:_updateValue() - old value:', _cut(this.value), ' new value:', _cut(this.get('value')));
+			this._set('value', this.get('value'));
+		},
+
 		_setValueAttr: function(value) {
 			if (!value) {
 				// remove content of youtube textbox and show initial label
@@ -170,8 +178,7 @@ define([
 			} else {
 				this._updateUploadedImagePreview(value);
 			}
-
-			this._set('value', this.get('value'));
+			this._updateValue();
 		},
 
 		_getValueAttr: function() {
@@ -234,7 +241,7 @@ define([
 
 		_updateUploadedImagePreview: function(/*image as base64 encoded string*/ value) {
 			// clear youtube thumbnail preview
-			this._setYoutubeVideThumbnailPreview();
+			this._setYoutubeVideoThumbnailPreview();
 			domClass.add(this._youtubeVideoThumbnailPreview.domNode, 'inactive');
 
 			this._setUploadedImagePreview(value);
@@ -253,20 +260,20 @@ define([
 			this._setUploadedImagePreview();
 			domClass.add(this._uploadedImgPreview.domNode, 'inactive');
 
-			this._setYoutubeVideThumbnailPreview(value);
+			this._setYoutubeVideoThumbnailPreview(value);
 			domClass.remove(this._youtubeVideoThumbnailPreview.domNode, 'inactive');
 			this.activePreview = this._youtubeVideoThumbnailPreview;
 
 			this.onThumbnailSet();
 		},
 
-		_setYoutubeVideThumbnailPreview: function(value) {
+		_setYoutubeVideoThumbnailPreview: function(value) {
 			this._youtubeVideoThumbnailPreview.set('value', value);
 		},
 
 		_clearPreviews: function() {
 			this._setUploadedImagePreview();
-			this._setYoutubeVideThumbnailPreview();
+			this._setYoutubeVideoThumbnailPreview();
 		},
 
 		// fires when a thumbnail is successfully set
diff --git a/univention-management-console-module-appcenter-selfservice/umc/js/appcenter-selfservice/ThumbnailDndList.js b/univention-management-console-module-appcenter-selfservice/umc/js/appcenter-selfservice/ThumbnailDndList.js
index e7c5538..28b2969 100644
--- a/univention-management-console-module-appcenter-selfservice/umc/js/appcenter-selfservice/ThumbnailDndList.js
+++ b/univention-management-console-module-appcenter-selfservice/umc/js/appcenter-selfservice/ThumbnailDndList.js
@@ -43,12 +43,18 @@ define([
 		_thumbnailBox: null,
 		initialBoxValue: null,
 
+		_updateValue: function(attr, oldVal, newVal) {
+			console.log('### ThumbnailDndTile:_updateValue() - old value:', this.value, ' new value:', this.get('value'), ' arguments:', arguments);
+			this._set('value', newVal);
+		},
+
 		buildRendering: function() {
 			this.inherited(arguments);
 
 			this._thumbnailBox = new ThumbnailBox({
 				value: this.initialBoxValue
 			});
+			this._thumbnailBox.watch('value', lang.hitch(this, '_updateValue'));
 
 			var styleContainer = put('div.styleContainer');
 			var leftNav = put('div.leftNav.dojoDndHandle');
@@ -120,11 +126,18 @@ define([
 		//     This reference is used so that there is always only one empty ThumbnailDndTile
 		_emptyTileNode: null,
 
+		labelPosition: 'top',
+
 		buildRendering: function() {
 			this.inherited(arguments);
 			this._createDndSource();
 		},
 
+		_updateValue: function() {
+			console.log('### ThumbnailDndList:_updateValue() - old value:', this.value, ' new value:', this.get('value'), ' arguments:', arguments);
+			this._set('value', this.get('value'));
+		},
+
 		_createDndSource: function() {
 			this.dndSource = new Source(this.domNode, {
 				type: ['thumbnailDndList'],
@@ -150,12 +163,13 @@ define([
 						'class': 'thumbnailDndTile',
 						disabled: this.get('disabled')
 					});
+					tile.watch('value', lang.hitch(this, '_updateValue'));
 					tile.on('deleteRequest', lang.hitch(this, '_destroyTile', tile));
 					tile.on('moveUp', lang.hitch(this, '_moveTile', tile, true));
 					tile.on('moveDown', lang.hitch(this, '_moveTile', tile, false));
 					tile.on('addBefore', lang.hitch(this, '_addEmptyTile', tile, true));
 					tile.on('addAfter', lang.hitch(this, '_addEmptyTile', tile, false));
-		
+
 					return {
 						node: tile.domNode,
 						data: tile,
@@ -175,6 +189,7 @@ define([
 			if (this.dndSource.getAllNodes().length === 0) {
 				this._addEmptyTile();
 			}
+			this._updateValue();
 		},
 
 		_moveTile: function(tile, before) {
@@ -184,6 +199,7 @@ define([
 				return;
 			}
 			put(referenceNode, putCombinator, tile.domNode);
+			this._updateValue();
 		},
 
 		_addEmptyTile: function(tile, before) {
@@ -224,6 +240,7 @@ define([
 			if (this.dndSource.getAllNodes().length === 0) {
 				this._addEmptyTile();
 			}
+			this._set('value', value);
 		},
 
 		_getValueAttr: function() {