Might be a bug... (Project organisation)
I can't reproduce the described misbehaviour. I also can't reproduce it in Milo's forum, which runs with the actual version 2.3.7.
I am not sure which version we have because I am not the forum owner. As an admin, I could only found the property "version" of value "2.3".
So I assume, that it should be the version 2.3.0 wich was released on september the 1st 2011. That said, I recommend an update, even it would be only about security issues.
On the other hand, some sources were replaced by Milo's version... I don't know... maybe it had an unpredicted impact.
Maybe it is. I know, that he uses not the standard theme. I don't know if he changed the forum script codewise.
I think you didn't mention: 3. the "new" style modifier is cleared from posts and threads after "Refresh".
Yes, that's point three. I subsumed it under point two (reset of the read status).
Anyway, this behaviour of "Refresh" seems inconsistent to me. It clears "new" posts and threads? OK. But it also clears "read" style modifier and this is not intuitive.
Trenne niemals Müll, denn er hat nur eine Silbe!