GNUS error "invalid function: (macro . #[(file &rest forms)"

[Sam Lowry]

This bug report will be sent to the Free Software Foundation,
 not to your local site managers!!
Please write in English, because the Emacs maintainers do not have
translators to read other languages for them.

In GNU Emacs 20.7.2 (i386-debian-linux-gnu, X toolkit)
 of Tue Jun 20 2000 on raven
configured using `configure  i386-debian-linux-gnu --prefix=/usr 
--sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var/lib 
--infodir=/usr/share/info --with-pop=yes --with-x=yes --with-x-toolkit=yes'

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

Emacs outputs this error message each time I press
f or F key in GNUS to post a reply to the group.

I started Emacs with --no-site-file and 
--no-init-file options but this did not help.


Recent input:
M-x g n u s return y down down down down down down 
down down down down return T H down down down down 
down down down down down down down down down down down 
down down down down down down down up up up up up up 
up up up return down return down return f C-x k return 
y e s return up up f6 down menu-bar help-menu report-emacs-bug 
C-g f6 up down C-x o down return f menu-bar help-menu 
report-emacs-bug

Recent messages:
Loading emacsbug...
Loading emacsbug...done
Quit
Mark set
Invalid function: (macro . #[(file &rest forms) "=c5=c6!=c5=c7!=c5=c8!=c9=ca
D=cb   =ccBF=cd=ce=cf=ceBE=d0=d1
DD=d2
=d3BB=d4        D=d5BB=d6=d4    D=d7=d8=d9=da
DDD=db=da
D=dcBBE=dd=de=df
=e0BBBB=afFE=d7=e1    D=e2    DEEE+D=87" [temp-results temp-buffer temp-file 
file forms make-symbol "temp-file" "temp-buffer" "temp-results" save-excursion] 
17 ("/usr/share/emacs/20.7/lisp/gnus/nnheader.elc" . 12653)])