asterisk users - May 2005 - Spa3000 doesn't hangup after a conversation

Hi,
I'm using a SPA 3000 as FXO and FXS termination connected to my * box.
I'm using the caller ID prefix trick explained here: 
http://www.voip-info.org/wiki-Sipura+3000.
All seems to work really fine, there is only a problem when I hangup my 
IP phone after a conversation and the other party don't: in this case 
the PSTN line remains connected until the other party hangs up.
Any ideas ?

There are settings in the advanced config to detect hangups or dropped lines
as well as timeout and sensitivity adjustments for them.
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Hi,
I'm using a SPA 3000 as FXO and FXS termination connected to my * box.
I'm using the caller ID prefix trick explained here: 
http://www.voip-info.org/wiki-Sipura+3000.
All seems to work really fine, there is only a problem when I hangup my 
IP phone after a conversation and the other party don't: in this case 
the PSTN line remains connected until the other party hangs up.
Any ideas ?