Problem I have is I have an iFrame pop up (page on same site) with a form in it. Setting the XID in this form has no effect on the parent page, so when the form is closed, refreshing the original page causes a internal server error, I suspect due to the XID issue.
I have no idea how to overcome this when using an iFrame. I need the iFrame because its a google map we do not want visible on the first page load, and google maps only work if visible on the page, so putting in an iframe fixed this issue, and now 2.7.2 breaks it.