FXO disconnect Issue

Question

I have a problem regarding the termination of FXO ports.
We have a call manager with IP Phones connected and a Cisco 2821
gateway with FXO ports.Now the issue is that when somebody calls
from PSTN to the IP Phone and disconnects the call before the IP PHone
user pick up the phone ,the IP PHone keeps ringing and the FXO port remains
up though the PSTN user has already disconnected the call.
I have read many documents regarding this issue on Cisco Web site.We successfully
resolved the issue but another problem arised after that.
NOw here are the 3 steps we did.
1)INitially we did not apply any configuration to the FXO ports .So we
were having the same problem as described above.
2)We applied the following configuration on the FXO Ports,
voice class custom-cptone 1
dualtone busy
dualtone ringback
dualtone reorder
dualtone out-of-service
dualtone number-unobtainable
dualtone disconnect
frequency 425 425
cadence 200 200 200 200
voice-port 0/1/0
supervisory disconnect anytone
supervisory custom-cptone 1
input gain -6
output attenuation 6
echo-cancel coverage 24
cptone SA
caller-id enable
The problem resolved succesfully .The FXO port goes on hook when the
PSTN user disconnects the call.
3)After applying the above config,we used a tcl script to provide
basic auto-attendant feature on the router.We started having the same FXO issue
again.Now based upon the above information ,how do u think we should
resolve the problem.

Answer 1

This URL should help you:
http://www.cisco.com/en/US/tech/tk652/tk653/technologies_tech_note09186a00800ae2d1.shtml