The default value for the `clienttimeout' variable in
/etc/inn.conf is 600 seconds, or 10 minutes. So if I am
running a local inn server and one of my users spends more
than 10 minutes reading an article, or writing a reply to
it, or if they even take a bathroom break, then INN will
drop the connection to the nnrpd client.

It's easy enough for me to change this myself, but it took
me two hours to find out what it was that I had to change.
Besides, 10 minutes is just way too short. I recommend that
you increase the default to at least 1800 (half an hour).