Index: ThumbnailView/ThumbnailWidget.cpp
===================================================================
--- ThumbnailView/ThumbnailWidget.cpp	(revision 662654)
+++ ThumbnailView/ThumbnailWidget.cpp	(working copy)
@@ -590,7 +593,8 @@
 
 void ThumbnailView::ThumbnailWidget::mousePressEvent( QMouseEvent* event )
 {
-    if (event->button() & MidButton )
+    if ( (event->button() & MidButton) ||
+         ((event->state() & Qt::ControlButton) && (event->state() & Qt::ShiftButton)) )
         _mouseHandler = &_gridResizeInteraction;
     else
         _mouseHandler = &_selectionInteraction;
