AA returns "you have entered an invalid ext." frequently

[ringbacktone]

I service a Norstar Mics (6.1) and a CP 150 (3.1) that stays on AA 24/7. When calling in and the Ext#266 is dialed the AA returns with you have entered and invalid number, then returns to the CCR tree Home menu. This happens on this particular call till you hang up. If it fails you can dial Ext 222 and get the call to go thru.
Loop start lines were swapped out for a channel bank , so calls are arriving to site via T1.
Any help or suggestions are greatly appreciated.
Thanks in advance, RBT

 

[phoneguy427]

If the problem started after the t1 install the circuit might be too hot coming in, you could ask your provider to put a pad on the circuit. Is it only ext 266 that has this problem or is this just an example? Can you dial 266 internally? if not you have other problems.

 

[ringbacktone]

I am going to go with the too hot approach. Could not help but notice that the AA greeting is too loud to the point of almost being distorted.
Will check it out .
Thank you