OS: Windows XP
Install-type: Windows Installer
Skin default
Firewall Software: no idea
Are you using IPV6? no
Is the issue reproducible? yes, but i fixed it with a faster machine.
Sorry, a bit of a crappy bug report.
I have been running on a dual xeon 450, (very very slow)
And get my downloads from a RSS list.
The problems occurs when a larger files gets downloaded, and starts to unpack, it takes a very very long time.
I guess the download does not get removed from download list, but only after unpacking, but Sabnzb is not downloading it, so it fetches it to download again because its neither finished nor downloading.
So in turn the file gets double downloaded.
I would guess the code would be something like and should include something like the bit i suggested:
if time to check again then Check RSS download list.
If not downloading and on the list,
then if not unpacking file then fetch nzb and download.
If file finished downloading then unpack.
if file finished unpacking remove from list.
If not downloading and on the list,
then if not unpacking file then fetch nzb and download.
If file finished downloading then unpack.
if file finished unpacking remove from list.
Might have already been fixed already in current version.

