It seems that Facebook stopped supporting the Internet Explorer 7 from Microsoft, according to The Sociable. Although it is not surprising since the browser is available for five years, IE7 may seem like a hack for those who do not like the newTimeline feature of Facebook. The navigation is not perfect, since together with the deactivation of the Timeline, the IE7 shows a little more white space, changing the look of the page.
This way everyone can have the old Facebook we all used for years.