OK - I'm restarting this. The problem is that usually Calibre is running, which moves the two original files, losing all evidence. The file duplication (and book duplication in Calibre) happens pretty often.
I just downloaded a file, and got a duplicate (Calibre not running). Here are the details:
group is alt.binaries.e-book
subject is : New eBooks 31 August 2015 - <tmi>.rar" yEnc
Post headers (if this is useful?)
Path: buffer2.nntp.dca1.giganews.com!Xby.tags.giganews.com!border2.nntp.dca1.giganews.com!nntp.giganews.com!news.alt.net!newsfeed.xs4all.nl!newsfeed8.news.xs4all.nl!feed.xsnews.nl!border03.ams.xsnews.nl!feeder04.ams.xsnews.nl!abp002.ams.xsnews.nl!frontend-F05-12.ams.reader.ssl-news.info
From:
fake@address.com (Psychopath)
Sender:
fake@address.comNewsgroups: alt.binaries.e-book,alt.binaries.e-book.flood
Subject: New eBooks 31 August 2015 - <tmi>
Organization: Psychopathy
X-Newsposter: Camelsystem Powerpost (Modified POWER-POST
http://powerpost.camelsystem.nl)
Message-ID: <part1of2.taDuvuDaXKNdEWbHiSG7@psychopath-powerpost.local>
Date: 05 Oct 2015 06:16:11 GMT
Lines: 3051
Bytes: 397006
Xref: number.nntp.giganews.com alt.binaries.e-book.flood:8122476 alt.binaries.e-book:45071451
<tmi> (mobi).mobi 627908
Two files were in my system:
<tmi> (mobi).rar
<tmi> (mobi).mobi
Meaning that both the rar and the result of decoding were left.
Using Newsbin version : 6.62: 00 06 39 F9 E2 60
thx,
.