>>>>> "Robert" == Robert Epprecht <epprecht@sunweb.ch> writes:

Robert> BTW: I got a different backtrace this morning, which was caused for
Robert> the first time by another group. I attach it, because it might
Robert> throw some light on the issue.

Robert> ================backtrace===================
Robert> Signaling: (error "Selecting deleted buffer")
Robert>   nntp-retrieve-articles((71810 71809 71774) "de.comp.os.unix.linux.misc" "new$  gnus-retrieve-articles((71810 71809 71774) "de.comp.os.unix.linux.misc")
Robert>   gnus-agent-fetch-articles("de.comp.os.unix.linux.misc" (71810 71809 71774))
Robert>   gnus-agent-fetch-group-1("de.comp.os.unix.linux.misc" (nntp "news.sunrise.ch$  gnus-agent-fetch-session()
Robert> * call-interactively(gnus-agent-fetch-session)
Robert> ============================================

Although you get different backtrace, the reason is the same.  Read my
article <2nu2r9yvuh.fsf@tiger.jia.vnet>.  The patch in the article
fixes part of this bug. Here is another patch.  You need apply both
patches.  I hope these can fix the bug.

1999-07-17  Shenghuo ZHU  <zsh@cs.rochester.edu>

	* nntp.el (nntp-kill-buffer): New function.
	* nntp.el: Use it to kill process buffer.