There should be no resistent data.
Do your projects use the same server? I.e. are the versions of PHP, MySQL etc the same?
I simply use the get_posts() function to do the query, so if the issue is in Content Aware Sidebars, the issue will be part of WordPress Core (which I think is unlikely in this case).
Do the error show up when you create any new page or only when you create a new page with a parent?