Fix to multi-delete in onetomany grid

inabox.wpf/DynamicGrid/DynamicOneToManyGrid.cs

@@ -237,9 +237,10 @@ namespace InABox.DynamicGrid
 
         protected override void DeleteItems(params CoreRow[] rows)
         {
-            foreach(var row in rows)
+            var items = rows.Select(LoadItem).ToList();
+            foreach(var item in items)
             {
-                Items.Remove(LoadItem(row));
+                Items.Remove(item);
             }
         }