Gah! How utterly annoying. In the latest update of the audioscrobbling client from Last.fm, version 126.96.36.199618, you are no longer able to hide the icon from the dock. And when uninstalling this version and re-installing the old version, 188.8.131.52240 (which you can download here Last.fm old version) it asks you to update on every launch of the application. Of course this update can be canceled but you can’t turn off automatic updates so it will keep on asking every time… sigh..
Update: They’re working on this. And they answered my email in like 20 minutes. I’m impressed!