Emacs may hang up while waiting for NNTP server responses. This may
be caused by a buggy select routine of your operating system. If so,
the problem may be solved by using source codes of `nntp.el'
instead of byte-compiled codes. If you still have problems with it, set
the variable nntp-buggy-select to t.
Emacs may hang up while retrieving headers of a large newsgroup. The
reason is that too many requests have been sent to the NNTP server
without reading replies to them. This causes a deadlock of Emacs and
the server. In this case, the number of requests sent to the server at
one time must be reduced. Set the variable nntp-maximum-request
to a lower value than the default. The optimal value depends on your
computing environment.