my browser version is Internet Explorer 8. So it keeps hanging in the browser whenever I try to edit, and sometimes I cannot see the WikiEditor toolbar at all (that usually happens before a hang).
I think you are hitting a known problem that I reported: https://bugzilla.wikimedia.org/show_bug.cgi?id=33926
To fix it for a user:
1. Click "My Preferences" 2. Click "Save"
The problem goes away. DanB