For the last 2.5 years, I’ve used the permalink structure:
One reason I did this is so that I could use a “shortcut” URL and get to a post with
http://www.domain.com/post_ID (without including the postname)
Since updating to 3.4 (I haven’t installed any other plug-ins), I now get a 404 if I go to domain.com/post_ID.
I’ve tried “resetting” the permalink structure by changing it to default, and then back… but that made no difference.
Suggestions? Clues? Or, better, a solution?