I have had this problem since I started using Calibre, and have just ignored it, as it is just an inconvience. However, I thought I would mention it as it does need to be fixed. Or, I need to be told what I am doing wrong
I am running Ubuntu 64bit.. this covers the last 3 major releases of Ubuntu. Every version of calibre for the last couple years. I pretty much update from the calibre website when a new release or update is posted.
When I go to shut down calibre, either by X'ing it out or right clicking on the icon in the unity bar at the left hand side of the screen and right clicking and choosing quit on the calibre icon the open window shuts. However it always leaves a calibre process running regardless if the gui is gone.
This affects two things for me.
1. If I run an update I have to kill that process before the update takes effect.
2. I run my library off of removable media. I can not unmount the media while the calibre process is running as it has files open on that media.
To shut down the process I typically use the gui system monitor and just end process. This works and only takes a second or two, but for a user not comfortable with managing processes at that level or at the command line, this would be an insolvable problem, which would require them to reboot the computer.