[asterisk-users] asterisk not detecting hangup

[Arkaitz]

Hi,
Im working with the following versions:
-asterisk-1.2.12.1
-zaptel-1.2.9.1
And with the following card:
00:0d.0 Communication controller: Tiger Jet Network Inc. Tiger3XX
Modem/ISDN interface
        Subsystem: Unknown device 8085:0003
        Flags: bus master, medium devsel, latency 32, IRQ 201
        I/O ports at c800 [size=256]
        Memory at fe000000 (32-bit, non-prefetchable) [size=4K]
        Capabilities: [40] Power Management version 2

Identified as:
*CLI> zap show status
Description                              Alarms     IRQ        bpviol
   CRC4
Wildcard X101P Board 1                   OK         0          0
   0

And the following lines in zapata.conf(for spanish lines):
answeronpolarityswitch=yes
hanguponpolarityswitch=yes

The problem is that although the calls work correctly the system is
unable to detect a pstn hangup and it keeps running even when the
other side is calling to another number(not an asterisk ones, asterisk
line keeps busy)
Any hint?
Thanks for your time
-- 
Arkaitz