In the past, Airtronics wired their servos differently than everyone else, and the new Z-connector is their attempt to be more like the standard. Here is a link to the Airtronics web-site to explain the new Z-connector:
http://www.airtronics.net/picture_shows_the_pin.htm
In the old servos, the Red wire is on the outside, opposite the signal wire (black w/ white stripe), and the new Z-connector has swapped it around with the ground so that the power (red) is in the middle like everyone else. If you are careful to make sure you get the polarity correct, you should be able to swap connectors. Otherwise you can buy the adapter cable from Airtronics.
Here's a link with diagrams of the common servo connectors at the bottom (except the new Z-connector):
http://www.fatlion.com/sailplanes/servos.html