We have set up a customer with an Asterisk @ Home 2.8 system (went in before Trixbox was out). It has four BT lines (we're in the UK) connected to four FXO ports on a Digium TDM400B card. The only advice/help I have had was to add OPERMODE=UK which I did - and it made the problem worse.
The problem is that at the end of just about every call, the system acts as though there is another call coming in. I believe this is caused by a battery drop or polarity reversal on the line to signal call disconnect being detected as a ring signal due to too little debounce.
How do I fix this, it's driving the client mad !