gnus won't give up asking for missing article

[Gary W. Swearingen]

I've just installed a new OS version with it's package of Gnus
v5.10.6.  While reading through a newsgroup, gnus gets into a
seemingly-infinite loop trying (unsucessfully, probably) to get the
same article (as seen in a nntp-log buffer).  Is there a way to limit
the retries?  (I'm fairly sure it's not 'nntp-connection-timeout'.)

Also, is it really necessary for it to send along to the NNTP
server my username and password with every request for an article?
Is there a problem with NNTP connections not being able to be 
kept open for long times because stateful firewall rules time
out and the authentication has to be done for each connection?

Thanks.