I have just updated jQuery & jQuery UI to: jquery-1.9.0.min.js and jquery-ui-1.9.2.min.js
And... all my unobtrusive Ajax calls (Ajax.ActionLink, Ajax.BeginForm) stopped working properly - they open results in a new page instead of updating the existing div.
The code hasn't changed of course, just updated the jQuery scripts using Nuget.
Anyone experienced the same problem ??