Firefox 3.5.x (including 3.5.10) does not freeze itself in this test page while Fireefox 3.6.x(including 3.6.0) does. And in Firefox 3.6x when the loaded web pages freezes, if the page has flash movies, those flash movies are not rendered at all. All other texts and images are loaded but they can not be selected and can not be clicked.
As far as I confirmed, this bug does not show up in Firefox 4.0 b1. It is confirmed only in Firefox 3.6.x.