having trouble getting this to work. Although I have a profile set up, when I try to play a stream from last.fm I get the error message "this feature is only available to last.fm subscribers" and nothing plays. When I click on the link to my last.fm profile within the Amarok settings dialogue, it takes me to my own account on last.fm

"this feature is only available to last.fm subscribers"

I suppose you aren't a subscriber, are you?

Is being a subscriber different to having an account?
I mean, the last.fm player itself works with my account, I just thought amarok would use the same details.

What Hans means is, that last.fm has two levels of membership. There is a paid subscription that gives you access to more streams.

Check the last.fm homepage for more information about what benefits you receive as a paid subscriber.