many error (bug?) messages on console

That's not a bug. It doesn't affect you in any way.

How is a message like:
"QVariantMap DBusMenuExporterDBus::GetProperties(int, const QStringList&): Condition failed: action"
not a problem? If it's not a problem, it shouldn't print to stderr.

I'm getting the same error message as the poster, the above error message is printed once for me, after opening Amarok in a terminal window "$ amarok"

If I run with --debug:
{{{
amarok: ************************************************************************************************************
amarok: ** DEBUGGING OUTPUT IS NOW ENABLED. PLEASE NOTE THAT YOU WILL ONLY SEE THE FULL OUTPUT ON THE NEXT START. **
amarok: ************************************************************************************************************
amarok: END__: static void App::handleCliArgs() - Took 0.00015s
amarok: END__: virtual int App::newInstance() - Took 0.00031s
amarok: BEGIN: void MainWindow::restoreLayout()
amarok: BEGIN: void MainWindow::layoutChanged()
amarok: [MainWindow] ignored: true
amarok: END__: void MainWindow::layoutChanged() - Took 6.9e-05s
amarok: BEGIN: void MainWindow::layoutChanged()
amarok: [MainWindow] ignored: true
amarok: END__: void MainWindow::layoutChanged() - Took 9.6e-05s
amarok: BEGIN: void MainWindow::layoutChanged()
amarok: [MainWindow] ignored: true
amarok: END__: void MainWindow::layoutChanged() - Took 0.00071s
amarok: BEGIN: void MainWindow::layoutChanged()
amarok: [MainWindow] ignored: true
amarok: END__: void MainWindow::layoutChanged() - Took 8e-05s
amarok: BEGIN: void MainWindow::layoutChanged()
amarok: [MainWindow] ignored: true
amarok: END__: void MainWindow::layoutChanged() - Took 6.3e-05s
amarok: BEGIN: void MainWindow::layoutChanged()
amarok: [MainWindow] ignored: true
amarok: END__: void MainWindow::layoutChanged() - Took 8.7e-05s
amarok: END__: void MainWindow::restoreLayout() - Took 0.12s
amarok: BEGIN: void Albums::dataUpdated(const QString&, const QHash<QString, QVariant>&)
amarok: END__: void Albums::dataUpdated(const QString&, const QHash<QString, QVariant>&) - Took 5.8e-05s
amarok: BEGIN: void CurrentTrack::dataUpdated(const QString&, const QHash<QString, QVariant>&)
amarok: END__: void CurrentTrack::dataUpdated(const QString&, const QHash<QString, QVariant>&) - Took 0.0001s
amarok: BEGIN: void Playlist::PrettyListView::fixInvisible()
amarok: END__: void Playlist::PrettyListView::fixInvisible() - Took 9e-05s
QVariantMap DBusMenuExporterDBus::GetProperties(int, const QStringList&): Condition failed: action
}}}

Running:
 * Ubuntu 10.04
 * Amarok 2.3.0
 * 2.6.32-21-generic

Vitals: Ubuntu 10.10, fresh install.

When running "amarok" from CLI, I am also having this printed to stderr:

QVariantMap DBusMenuExporterDBus::GetProperties(int, const QStringList&): Condition failed: action

During playback of music files, the music will skip and that message will print to the CLI at the same time as the skip. That's if amarok starts at all. I can get it to start once if I rm -rf .kde/share/apps/amarok/

So, if I rm the amarok directory as above and start it with amarok --debug, it works normally until I close it. However it still prints the above message to stderr if I click or interact with the tray icon in any way. It will also print when changing song, even with all kinds of notifications disabled.

After I close Amarok normally and start it again with amarok --debug, this is printed, seemingly endlessly (on a 2.67Ghz Core i7, I've let it run for ~5 minutes with no end). The tray icon appears in the tray, but the option to maximise/open Amarok is greyed out and the tray icon doesn't respond in any meaningful way.

amarok: our service is not ready! queuing track and returning proxy
amarok: our service is not ready! queuing track and returning proxy
amarok: BEGIN: virtual void Playlist::Model::metadataChanged(Meta::TrackPtr)
amarok: [Playlist::Model] Metadata updated for track ""
amarok: END__: virtual void Playlist::Model::metadataChanged(Meta::TrackPtr) - Took 0.00052s
amarok: our service is not ready! queuing track and returning proxy
amarok: our service is not ready! queuing track and returning proxy
amarok: BEGIN: virtual void Playlist::Model::metadataChanged(Meta::TrackPtr)
amarok: [Playlist::Model] Metadata updated for track ""
amarok: END__: virtual void Playlist::Model::metadataChanged(Meta::TrackPtr) - Took 0.00056s
amarok: our service is not ready! queuing track and returning proxy
amarok: our service is not ready! queuing track and returning proxy
amarok: BEGIN: virtual void Playlist::Model::metadataChanged(Meta::TrackPtr)
amarok: [Playlist::Model] Metadata updated for track ""
amarok: END__: virtual void Playlist::Model::metadataChanged(Meta::TrackPtr) - Took 0.00053s
amarok: our service is not ready! queuing track and returning proxy
amarok: our service is not ready! queuing track and returning proxy
amarok: BEGIN: virtual void Playlist::Model::metadataChanged(Meta::TrackPtr)
amarok: [Playlist::Model] Metadata updated for track ""
amarok: END__: virtual void Playlist::Model::metadataChanged(Meta::TrackPtr) - Took 0.00057s

Jonathan, would you please post a comment about why you changed the status to 'invalid'?

Same error here...
Ubuntu 10.10 Maverick, running Amarok in Gnome, and playing a wma file.
I don't understand why the status of this bug was set to "Invalid" too, since the debug says "Application Amarok crashing" by the KCrash.
Please, do a best explain to us why you changed this bug to invalid.
For me, if a app crashes, may be a bug.

I get the same error message too, although I've compiled Amarok from git so can't complain. Not sure why exactly that appears and whether or not it's a problem. I was unable to play music files too, but then found that mp3 and wma were not playable while ogg files were. Then installed the required plugins and the files now play properly, but this error message still appears in debug output. So I don't think it's related to playing of music files.

Searched in google and this seems to be happening to other KDE programs too. I think it's not Amarok specific.