I have a Lenovo W520 that I recently installed Disco Dingo on. Everything seems to work great, including the fingerprint scanner, with one minor annoyance: I can't login with the fingerprint scanner from the initial login screen. I can login from the lock screen with the fingerprint scanner, but when I try to utilize the fingerprint scanner for the initial login screen, it seems to attempt to log me in (the blinking light on the scanner goes out as normal - it will blink rapidly if the fingerprint wasn't recognized), the login screen disappears and appears to log me in, but then it just loops back to the main login screen again.
If I enter my password, it works fine.