The greeter doesn't pick up fprintd's fingerprint readings

[Zisu Andrei]

Recently saw a driver was developed for the fingerprint sensor my laptop has, so I installed fprint according to https://launchpad.net/~fingerprint/+archive/ubuntu/fprint

I have configured it and it works fine with sudo and (I believe it is called) gksu.

The following line is present in /etc/pam.d/common-auth:

auth [success=2 default=ignore] pam_fprintd.so timeout=10 # debug

In the greeter, there is no feedback about about fingerprint login being present or fingerprint strokes happening (in the case they have failed).

So, it's either:
a) the login screen doesn't know about the configuration so it doesn't act accordingly
b) the fingerprint strokes are registered, but they are unsuccessfull, but there is no feedback presented

Is there anyone who can advise on how I can identify the problem? I can even try and fix it if pointed to the right place (i.e. source-code location).