[asterisk-users] Asterisk - Spandsp Fax not working?

Hi all,
I'm trying to setup an asterisk based fax receiving machine.
i'm using asterisk 1.2.18 and app_rxfax with spandsp 0.0.4pre9
I have no problems with a modem-fax, but with the fax machines i have tried almost every fax fails, both in sending and receive.
the machines are sending a receiving a lot of faxes every day and working well, so i think the problem is on the spandsp side.
i have tried almost every spandsp version from 0.0.2 to the current one, both with and without ECM, but without luck.
has anybody succeeded in receiving faxes with asterisk app_rxfax and spandsp?

I'm noticicing a lot of different behaviours: sending w ECM gave me an OK, and the second half of the page was missing, other faxes fail with
Sep 26 17:26:18 DEBUG[4741] app_rxfax.c: ==============================================================================
Sep 26 17:26:18 DEBUG[4741] app_rxfax.c: Fax receive not successful - result (11) Unexpected message received.
Sep 26 17:26:18 DEBUG[4741] app_rxfax.c: ==============================================================================


can anybody help me?
thank you in advance,


marco