Triaggers : - for a bug that reports bad page splitting / missing pages in print or print preview, and you have no idea if it's a dup of an existing problem, mark as blocking this bug - if you strongly suspect it's a dupe of a problem in the list of those blocking this bug, mark it as depending on *that* bug. Leave a comment on the bug that if solving the depending bug doesn't solve the problem, the bug should be changed to blocking this one - if you have *demonstrated* it's a dupe of an existing problem, close it by duping to that bug. But add a comment to the duped bug with the url of the problem. In the first two case, please try to extract a reproducible test case from the page. If you don't have much time, don't try to minimize it, but *do* try to save it as a workable test case somewhere. If this is not done, the page will very probably have changed by the time someone wants to check what the problem consist of exactly or if it is corrected by some fix, and the usefulness of the bug will be reduced to about zero.
Problem is still exists in Firefox trunk 53 version, we can reproduce this problem via try to print this page: http://semantic-ui.com/ - this only one example, but in real I can't print many sites! This is serious problem!