Version:           1.7 (using KDE 4.7.1) 
OS:                Linux

Here is description:

I open some .torrent file for the first time.
Options dialog appears, I check 'Move torrent file to Trash', click 'Open'
Everything's okay, torrent added and .torrent file deleted. But.
I open one more .torrent file
Options dialog appears, I check again, click 'Open'
Torrent added, but .torrent file is still in a folder.
It happens when I open .torrent files using file manager (Dolphin) or using Chromium|Firefox after download. After restarting the client first added .torrent file succesfully moves to trash, but the others don't.

Similar bug with transmission-qt people:
https://trac.transmissionbt.com/ticket/4036

my guess is that Dolphin has the same problem, which really looks like a Dolphin bug since it shouldn't open or lock the file, just run the open action passing the file name (path) as parameter.

Reproducible: Always

Steps to Reproduce:
In KDE for transmission-qt
Go to Edit menu > Preferences > Click Move .torrent file to the trash.
Hit close
Try to download a torrent. The .torrent file will stay in your downloads folder.

Actual Results:  
In XFCE, .torrent file is moved to trash using transmission-gtk.
In KDE, neither transmission-gtk or transmission-qt move .torrent to trash.

Expected Results:  
.torrent file moves to trash so it doesn't clutter download folder.

Archlinux Bugreport
https://bugs.archlinux.org/task/26072