It seems as if the instant e-mail notification is a bit overactive, I seem to be getting one for every new post in a thread. All that's really necessary is to receive one after leaving the forums. Otherwise, if there are 23 replies to a thread you'd get 23 e-mails. It just seems like a waist of resources to me.

i've just done a test and it actually works as it should.
But I think that when you browse the forum for a longer period and new posts are being made while you browse, you get a notification for every post, because each time you load a page here, your 'have visited' value is reset (or something like that ), so with every new post, the forum thinks 'gotta send him a notification'.

And that's why I don't use subscribe at all anymore. :-)
I can always come in when I have the time and look through all threads which have new posts...