Luckily I made a backup of the database 4 days ago.
I assume I'll need to restore the posts manually though.
And there are indeed some posts/topics missing. (The last topic in the Arcade: Capcom forum was "Street Fighter II: The World Warrior".)
EDIT1: Okay, that's weird. The post exists in the DB, the topic too, but it still doesn't find it. This will need some debugging I guess.
EDIT2: Ohhh ... the problem is not that posts are missing, the problem is that a user (or more users?) is missing!
In this case, dissident93's entry disappeared.
It looks like re-inserting dissident93's table entry fixed everything.
I also compared the database dump from today with the one from 8 June and I think I didn't miss anything else.
If you think anything is still wrong, please report it.
Thanks.