I can never be sure, but I'm fairly certain I'm not going crazy.
Occasionally I'll be browsing the forum or checking my PMs and see something new. Then I'll see the time it was posted/sent and it was before the last time I checked. So, for instance, yesterday I got a PM at 6:14am, but despite being on the forum a few times throughout the day, the message didn't show up until mid-afternoon. I'm pretty sure it's not a matter of time zones being off because when I post/reply it shows the current time.
Please tell me I'm not crazy. Of course, that's exactly what a crazy person would say.
I'm actually running into a similar issue to yours, in tandem with the one I described in my thread below.