asterisk users - Jan 2005 - Asterisk doesn't detect when the caller hangs up

Hi all.

I've installed a TDM card, with 1 FXO port. I've configured the zaptel 
driver and everything seems to be ok: Asterisk answers the calls. Now, 
the problem is that even when the caller hangs up ("the caller" is my 
self from another PSTN line) Asterisk doesn't detect it, and it goes on 
processing the current context in extensions.conf as if the call was 
still active.

Im in Spain, and I cant find any reference to the parameters to modify 
to make asterisk detect the hang up. Any help is appreciate, as always :)

Att,

RODOLFO