Several days ago (~05 Feb 2008) scrobbling audio tracks to last.fm stopped working.

What is scrobbling?

"Scrobbling a song means that when you listen to it, the name of the song is sent to Last.fm and added to your music profile."

Yep. I listen to music, a player sends track names to some server (post2.audioscrobbler.com), and you can see nice charts on my profile page.

Everything works fine until it breaks.

I suspected firewall (iptables) that had been enabled recently. But even without any firewall my player (amarok) continued displaying "Failed to submit several tracks to last.fm" error.

Fortunately, enforced with network tools (tcpdump and wireshark), I've found the proper google search keyword - BADAUTH - located in HTTP server response.

Googling was fruitful this time: the solution is to reset [the same] password at last.fm site.

"The reason for this was said to be that the hash on last.fm database for our password was corrupted due to some update on their database or something, so if you retype the password it should work."