Fix issue related to context menu display in the PropertyGrid

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/wpfdesigner@5947 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/PropertyGrid/PropertyGridView.xaml.cs

@@ -64,7 +64,7 @@ namespace ICSharpCode.WpfDesign.Designer.PropertyGrid
 			}
 		}
 
-		protected override void OnMouseRightButtonDown(MouseButtonEventArgs e)
+		protected override void OnMouseRightButtonUp(MouseButtonEventArgs e)
 		{
 			var ancestors = (e.OriginalSource as DependencyObject).GetVisualAncestors();
 			Border row = ancestors.OfType<Border>().Where(b => b.Name == "uxPropertyNodeRow").FirstOrDefault();