In my ongoing battles with iD, here's another. I want to make a cross reference to another document in the same book, sort of "see the Light section starting page xxx". I have my Light document open at the same time as the one I am currently editing and I clicked on new cross-reference. I also have some of the other documents of the book open. In the Cross-Reference panel, where I choose Link To and Destination I have Paragraph to link to a Para Style, but when I change the destination to my Light doc it switches immediately back to the doc I'm in. It will stay on some of the other docs that are open, but that's not the point, it won't stay on the one I want. I have recently exported this whole book as IDML to sort out a different problem (not that it did) and now have this to contend with as well.