Calls from a SIP channel don't hang up

I have route the inbound call to a ring group and for a reason asterisk don’t hang up even when the caller does and if none answer the call it ring indefinitely.

I found the same problem in dahi but the solution apply to sip… I guess http://www.freepbx.org/forum/freepbx/general-help/calls-from-a-dahdi-channel-dont-hang-up

What could be happen?