How does the original author of a question get to create a duplicate title but an editor of the question (who didn't even change the title) gets told that it can't be edited because a question of that title already exists? The question under debate is now called Segmentation Fault (core dumped)...BMH Algorithm, where I added the 'BMH Algorithm' to get past the uniqueness filter. (Don't get me wrong; the title wasn't great — but it was acceptable when the question was asked, so why wasn't acceptable when the question was edited?)
There's a question about this from January 2012 with 'status-completed'. If it was fixed back then, it is now unfixed again.