It would appear that Notifications are broken for many users now, along with the already mentioned problems with getting error messages that lead to a lot of double posts. At first, I thought that I just wasn't getting replied to very much this weekend, but since Friday, it appears that no Notifications have been going out for forum post replies. I've found over ten or so posts that I was never notified about.
The only Notifications I am receiving are from PMs. So, even if you reply here, I'm likely not going to get notified about it. Hopefully this is related to the same problem that has led to the error messages other members have mentioned and they can be fixed on Monday when the staff are back in. Help us, @alexisg! You're our only hope!
I have heard similar complaints from a few other users, but I'm guessing this is a wider issue than it seemed at first. So, any of you affected by this as well?