I am getting the same issues as Vishy Moghan.
Removing the jetpack directory from plugins via FTP ‘fixed’ the problem.
“Deactivating” the Jetpack plugin takes me to the sites 404 page.
When the Jetpack plugin is activated, and I go to Appearance -> Widgets, the sidebar to drag the widget to is not shown and only a couple of the widgets appear.
Themes: 2011 v1.6 and 2013 v1.0
WordPress v.3.6