Hi, there,

The error get signaled when I add "text/html" to
`mm-inline-override-types' (my mailcap says to use lynx and
`needsterminal'), because `mm-remove-part' kills the article buffer
unintentionally:

(kill-buffer (cdr object)), while object contains no buffer but only
tmpfile name, so it kills current buffer (article buffer).  I'm not
very sure the patch is the real cure due to lack of knowledge of whole
package, though it works.  Maybe `kill-buffer' in `mm-remove-part'
should be guarded?