Just realised what you said here. What do you mean "Log In"? This is a
public
newsgroup and no login is required. You could well be better off using an
application designed for accessing newsgroups, at the very least Outlook
Express will do that for you.

I tried to test this by clicking "Reply". Apart from that that I received an
error page for the n-th time again, in the fourth, finally successful attempt
I was propmted for log-in. So obviously I cannot participate in the
discussion without a registration.

RSS supports threading messages (my reader is RSSOwl).