LI> I thought this was about nnml?  Is ~/Maildir/new/Z your nnml directory?

No. I just made a file where gnus gets its mail from when I hit "g".
g runs the command gnus-group-get-new-news

Anyway, all you need to do to reproduce this bug, is to have somebody
send you a mail with raw UTF-8 in the Subject header.

LI> There was just ASCII in the part you posted.  Could you gzip it, as I
LI> asked you to?

$ perl -nwle 'print if /\P{ASCII}/' Mail/mail/misc/.overview > /tmp/h
$ gzip /tmp/h