One of the more annoying little things that I’ve always found with AdSense is that in the setting up of a new ad unit you do all the design aspects of it and then get to the point of adding a channel. IF you want to make a new channel for the ad you’re currently making you need to leave the process to do so and in doing so loose all your design settings.
This seems to have been changed in the last 24 hours because now when you get to the point of choosing a channel there is an option to ‘Add new channel’.
When you click this link it opens a popup box to allow you to do so without loosing all your previous information.
I’m not sure when this was added but I don’t remember it there yesterday when I was making a new ad.
Thanks to Duncan for the email tip off.