Yeah, yahoo marking the notifications as spam was what the problem! Looks like it started some time after Thanksgiving when massive retail advertisements are flooding people's email accounts (at least those who buy stuff online, like me).

I've never encountered something like this either. And it's not limited to LJ, some of my work related emails got misplaced as well. I had to bug my system admin to troubleshoot, and we never zeroed in on what was the problem. I just found out all those "missing" emails ended up in my Spam folder! *sigh*

Thank you so much for your support, luv! *HUGS*