asterisk users - Apr 2005 - Urgent .... Asterisk <-> Cisco CCM SIP TRUNK

Hi All,

I'm getting a strange problem with asterisk 1.0.6.
I've got a SIP Trunk between CCM 4.1 and Asterisk 1.0.6.  We are
talking about a daily average of 900 calls, and 600 minutes.

I'm running in asterisk 3 queues, 2 of them with dynamic members
(chan_local), and one with only one static member, and a Voicemail system.

Since yerstaday (i wonder why?), and only sometimes, when a call enter
a queue, it starts ringing a member phone, and when he tries to pickup
the call it jumps to other queue member, and when the other queue
member pick up the call, it jumps again to other queue member ....
they are getting crazy !!!! .... until one of thems catchs the call.

When it happens, in the next seconds if i try to dial to asterisk, CCM
gives-me a busy tone, but nothing reachs asterisk box, i dont now why
CCM's gives busy tone without sending the call to asterisk !!! Is this
a CCM feature ?

All the phones used are cisco (skinny) attached to CCM.

The only thing that appears on logs is:

    file.c:550 in ast_readaudio_callback: Failed to write frame.


Thanks in advance

Regards
       Jo?o Amaro