double repeat symbol

I read about how you can put a double measure repeat in your custom palette, I should think it belongs in with repeats and jumps, so I did everything it said, and I tried to drag it to a palette like the doc said and It wouldn't go there. I was able to drag it on to my score. Yes I had editing enabled. I tried it with the palette rolled down and rolled up. it says just a normal drag for a palette and a normal drag works for the score but I can't get it on the custom palette. What am I doing wrong?