It's because when the answering machine picks up, the trunk stops ringing and the ctx now considers it an idle trunk. When you select the trunk that the answering machine has siezed the ctx thinks that you're trying to make an outbound call and won't cut the trunk through to you until you dial a phone number that matches the dialing plan. Dialing 411 for example would work because 411 is part of the dialing plan N11. If this is too much of a hassle, you can enable immediate cut-through on the trunks if the redial feature is not important to you. By the way, if you have a spare analog station, place the answering machine on it and have the trunks delay ring to it. That is a more elagant way of doing it and you'll only need 1 answering machine.
