>I’ve also had reports from other users that after entering the password, they are redirected to the wp-admin/ logon screen.
I have solved this issue.
The issue was occurring when using the non-www version (the site is officially at the www url).
yoursite.com/index.php/passworded/ (did not work)
https://www.yoursite.com/index.php/passworded/ (worked)
I’ve redirected all traffic to the www url.
I’m still seeing the wp-pass.php problem on Firefox 3.6.3 on a Mac but this seems to be specific to my machine.