I think I just found a bug with guides shared with all layouts in a file. I was working on a layout in one window, then opened another layout in another window to set guides to use in the first layout I was working on. The guides set-up in the second window were not available to the layout in the first window, despite the "Share Guide with All Layouts" option being on. If I went to another layout in the second window or opened a third window, the shared guides were available in those windows. Has anyone else encountered this?