There seems to be a problem in the URL construction for the 'Manage Subscriptions' link on the top panel in 1 case.
-> Click on Subscriptions->'Read my Subscriptions'.
->Then after page load click on 'Manage My Subscriptions'.
-> Page not found error resulting in blank section of page. (link shown is http://en.wordpress.com/subs&p=subscriptions.manage.blogs)
-> IF now you click on 'Manage my subscriptions' again, then correct URL is shown as http://en.wordpress.com/#subs&p=subscriptions.manage.blogs & page is displayed properly.