Ordering of "threaded by subject" messages

I read a newsgroup where the messages are gatewayed from both a web
forum and a mailing list. Thus, while some threads have proper
References: in the headers joining them, up other threads don't and tin
just does its best on the basis of the Subject: being the same.

I'd like the non-References threads to be sorted by date rather than
the (apparently) random order they appear in at the moment.

So I assumed I needed to set sort_threads_type=4 in my tinrc.  But it
doesn't seem to work, I still get an apparently random order when
viewing a thread which doesn't have any References:.

I have done "rtin -u" but it didn't seem to change anything.  This
*should* do what I want shouldn't it?

While I'm about it I assume that sorting by date won't override the
actual References: will it?  I just want threading by References: when
they're available and threading by date if they're not.


-- 
Chris Green