Thread subscriptions disappeared

[Octo-puss]

Is there any logical explanation for this?
I've just noticed that subscription to several threads disappeared from my CP without me doing anything, and I mean nothing at all.
The threads are still here, of course.

[Octo-puss]

No admin wants to bother to explain? Great.

[Octo-puss]

And again!
I only changed the email on my account and now I've noticed most of my active thread subscriptions diseappeared. Something's bugged in the forum software, apparently.