I upgraded to Movabletype 3.16, and it has an annoying bug for users who have it installed in the root directory of a domain or subdomain, as I do: it refuses to stay signed in, kicking you back to the login form between every click and every action. The problem is a few lines in lib/MT/App.pm, but the fix suggested in the MT support forum is rather cryptic. Thankfully, Wishingline.com has a mofidied App.pm ready to download.