I received a couple of comments on my article about making the pull-down-to-refresh work with a Windows Phone virtualizing list control.
The problem was that the functionality stopped working after navigating away from the page containing the ItemsControl.
To prevent events from triggering when the list is not in view I deregistered all events. But when the list came back in view I didn't start monitoring these events again.
Today I committed the code to GitHub to fix this issue.
You can download my Windows Phone 8 example project on GitHub.