I am not a great KWallet fan (probably due to ignorance), so when I introduce my Last.fm credentials in Amarok I get this warning that they will be saved in plain text (because Kwallet is not running). That didn't bother me much, until recently. As it happens, my computer at work (Amarok 2.3 on Arch Linux) does not scrobble (publish) the tracks I play into Last.fm.
The root of the problem seems to be that my Last.fm credentials are not actually saved. If I go to Settings -> Configure Amarok -> Internet Services -> Last.fm, I can write my "Username" and "Password" there. If I click on "Test login", it will report a success for valid credentials, and a failure for wrong ones. If I click "OK" (that is, save and exit), the aforementioned warning about Kwallet not running appears (no big deal so far), and if I choose to accept the proposal of saving the password in plain text Amarok seems to accept it. The problem is, it doesn't really. My tracks don't get scrobbled, and if I go to the Last.fm settings again, the credentials are empty.
In my computer at home, with an identical Amarok 2.3 on Arch Linux and with no Kwallet, the credentials do get saved, and the scrobbling does work. It might well be because I alreadly applied the trick I will explain next (and I don't remember having done it). I came accross the solution at bug report 555688 at Launchpad, the Ubuntu bugtracking site.
The solution is simple. Edit the following file:
and add the following (section
[Service_LastFm] will most likely already exist):
YOURUSERNAME must obviously be changed for the appropriate values.