Apparently the "last post" in the info center, reacts to the latest topic, not message.
Is that different that what it used to be? (now I'm being lazy)
Actually, now that I tested a bit more, it looks like the only board that here at elk.net triggers the latest post is Feature Discussion, any other board I tried doesn't update the latest message.
Now, it's something odd happening only here or something broken?...
It seems part of the problem is the cache, probably the message is cached for a long period of time and is not updated promptly when a new message is posted.
I wouldn't consider it a huge bug, just something to look into in future (maybe it's possible to clean a cache entry, maybe the one corresponding to the user that last posted, that should ensure a faster update).
Maybe ajaxify that area and poll every 30 seconds or whatever to refresh the area?