First off I have a datagrid on the main form which is populated with about 7000 rows. It is bound (to ItemsSource) in the forms constructor. Everything runs extremely fast and smooth when the app loads (less than 1 sec). However when I want to load that same datagrid in another window it takes > 1 min. There is no difference in the xaml between pages. What could be causing this. I am using Virtualizing Stack panel as well as turning on Cell and Row Virtualization on the DataGrid. I have profile my Sql Server and the query runs in the same time for both calls so it's not a database issue.
I got curious and set up a listview and bound it to the same source on the second form and the same scenario happens as well.
What could be the issue?