Inconsistent behavior when quitting rhythmbox

For a user there are three ways I know for quitting an application :
- File->quit
- Alt+F4
- Click on the cross of the window
- Right click on the icon in the dash and select quit

According to these 4 methods there are two cases to consider : either a music is played or not.

While not playing : the application is always unloaded from the memory whichever the way used (that is good)

While playing : only the quit option in the file menu really unload the application. The three others options rather hide the main windows (background play) so that :
- it is impossible to remove the application from the memory without opening a new window;
- it is difficult to predict what will be the behavior of closing the window or using the dash quit option.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: rhythmbox 2.98-0ubuntu5
ProcVersionSignature: Ubuntu 3.8.0-33.48-generic 3.8.13.11
Uname: Linux 3.8.0-33-generic i686
ApportVersion: 2.9.2-0ubuntu8.5
Architecture: i386
Date: Sun Dec 8 22:09:52 2013
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/rhythmbox
InstallationDate: Installed on 2013-06-10 (181 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release i386 (20130424)
MarkForUpload: True
SourcePackage: rhythmbox
UpgradeStatus: No upgrade log present (probably fresh install)