ASP .Net Update Panel partial postbacks stop working when using Javascript window.history.pushState() in front end

I have a business requirement where all page URLs should be hidden so the user doesn’t actually know what page they are on when browsing.

I am using window.history.pushState(‘string’, ‘My Software’, ‘/MyPage’) on all my pages to acheive this. It works fine i.e. all links on the site appear like mysite.com/MyPage. But, whenever we use an update panel for things like modal popup viewers and other things that cause a partial postback, none of that stuff works.

I am using Visual Studio 2010 + ASP.NET 4 Webforms.