The username field on sites where I have a saved username/password doesn't autofill. You have to type the first letter of the username and then will the rest fill in. Which defeats the whole purpose of autofill because if I could remember the first letter I could remember the whole username. The arrow keys and any kind of clicking in the name field do nothing. Also, I have tried setting the signon.autofillForms pref to true and to false and neither solves the problem. The exception is on that tiny handful of sites (such as Gmail) where I have more than one account, i.e. two or more username/password combinations. For those, you type the down-arrow and a drop-down list of usernames appears. This is exactly what SHOULD happen on all the other sites.