After logging in as admin, social activities block always looks in edit mode without pressing the button, "Turn editing on". This happens in all the courses. When a student logs in or for a guest visitor it looks normal. This has happened after upgrading from 1.5.3+ to 1.7.
I have also noticed the same issue after a fresh install of 1.7 in another server and restoring one of the backed up courses of 1.5.3+.
It is also reported that the same problem is observed after upgrading from 1.6.2 to 1.7 (http://moodle.org/mod/forum/discuss.php?d=59004).