HSF modem don't send RING message

I'have successfully installed HSF Drivers of my conexant modem on CentOS 4.4.

on minicom interface i send and receive fax manually (with atdt end  
ata commands). But when i receive an incoming call the "RING" message  
it not be displayed.

[root@server hylafax]# hsfconfig --info
Conexant HSF softmodem driver, version 7.47.00.03full

If you need license keys, assistance or more information, please go to:
         http://www.linuxant.com/

When reporting a problem for the first time, please send
us the file generated by "hsfconfig --dumpdiag".

Note: HDA support not compiled in the driver

Note: kernel module snd-intel8x0m overridden by hsfmc97ich hsfmc97sis
Note: kernel module snd-atiixp-modem overridden by hsfmc97ati

Current parameters: ("hsfconfig --info")

Config for modem unit 0: /dev/ttySHSF0
         Device instance: 0-PCI-14f1:2f30-14f1:205d
         HW revision    : Basic2 2.18 Standard DAA 3VoltsIA
         HW profile name: hsfpcibasic2hsfi
         Registration ID: AFF9-BE8D-2BA7
         License owner  : [email protected]
         License key    : E6-C7-A7-21-3B-DA
         License status : OK
         Current region : ITALY (T.35 code: 0059)

The /dev/modem alias (symlink) points to ttySHSF0