"Notify me of responses via email" gets unchecked regularly


I have noticed that around half of the time (maybe more), I don't receive email notification of responses to the threads I start here. Then, when I visit them (after seeing via my recent activity page that there were in fact responses), the "BE NOTIFIED OF FOLLOW-UP POSTS VIA EMAIL" is not checked off, even though it was checked off when I started the thread.

This has happened many many times; most recently here:
and here:

In both of those cases, it was checked off when I submitted the thread, and I didn't get notified that there was a response, and when I went to revisit the thread, the box was unchecked.

I've mentioned this in the threads themselves most of the time when it happens, but no one seems to respond to it there, and apparently it hasn't been fixed, so I figured I should start a thread about it.