>They are now building 2 combs on most frames, so the frames stick together. I had forgotten to push the frames together, and they used the extra space. My bad.
That's a problem even with foundation, but with foundationless they will perpetuate any problem on down the line. I would cut them out and tie them into frames.http://www.bushfarms.com/beespackages.htm#dontleavemessedupcomb
>I added another medium a week ago, they are doing the same thing in that one.
The sooner you fix it the better.
>Do I just cut out the extra comb? Treat that comb like a cutout?
Yes. Just like a cutout.
>I've added a frame of plasticell in the middle of each box, hoping they'll see the light.
That may help with getting them in the right direction, but that doesn't seem to be the problem. It may not help with the getting them in the center of the frame. Do you have a comb guide? Does it stick out well? If you don't have a guide they tend to build on the edges of the top bar.