Yup, it's the way it works. There is a delay becuase it takes a bit of time before last.fm scrobbles the song and for the plugin to get the last song. This means that sometimes (for instance when you listen to a song that is 10 minutes or longer) you'll see the "was listening to". Anyway: there is always a delay. You could lower down the delay for faster synchronization, but last.fm needs it time to scrobble anyway. Conclusion: it's not real-time like the iTunes plugin (which works on the same computer), but for me I see no problem. The fact that you want people to show them your music is about the music and your identity that comes along with it... So what it's 3 minutes later?

I've added a "Customization" tutorial in the Xtras description. Good luck!