Ummmm......I feel your pain
I've not found a way to remove the AB devil, BUT.....if you're willing to spend a little time, there's a way to put the troublesome AB problem in a corner, sort of, and I may be telling you something you already know. The requirement is that you haven't done that A or B or AB thing to all the zones.
The goal is to move the zone or zones with the AB problem to the bottom of the zone list, change the scan mode for the scan list assigned to that zone to Normal. If you've already filled the zones with channels and chosen an A or B or AB in each, then this post is moot.
First, if you haven't already done this, double click on the A or B field and select AB so as to get both into one field. This way you only have to concern yourself with one line with the AB thingie going on.
Go to Zone Operation > Zone 1(or whatever), right click on the alias (name) field, left click Down, and repeat the Down thing with each zone until you get all the zones that have the little AB bastar.....uh, troublemakers to the bottom of the zone list.
Then go to the first zone which should now be Zone 1, create the required number of channel lines, go back to the old Zone 1 (which is now renumbered) and highlight all BUT the one with the AB problem and right click and select Copy. DO NOT Copy the line with AB! This means you'll have to manually duplicate the one line that has the AB thingie.
Now, go to the new zone, right click in the first open line and right click Paste to place the highlighted channels to the new zone. Go back to the zone you just copied from and highlight and erase the channels or you may exceed the number of channels available on the next try.
If you don't need to have a 1st and 2nd priority, the other alternative is to go to Scan List and change the Scan Mode to something that uses the selected channel instead of the AB tagging, but again, that means a single priority per scan list.
Hope this helps some, and if anybody knows a real way around this joyful software feature, please post it.