All right. I have done a canola-cleanup and reinstalled everything from scratch. Here is what I have found:

* When Shuffle and Repeat options are OFF (using menu in the audio player module), Last.fm "next-song" button is responsive, it works like a charm. Unfortunately, Last.fm still does not switch to the next song automatically when the current song ends. You have to press "next-song" button.

* When Shuffle and Repeat options are ON (and you have to go into audio player module to toggle them again), Last.fm "next-song" button becomes unresponsive, you have to click it multiple times to get to the next song. Last.fm STILL DOES NOT SWITCH to the next song automatically when the current song ends.

Now, I have run "/usr/bin/canola -vvv" from ssh, got into Last.fm module, started playback, and pressed the "next-song" button. The button did not work, but here is what I have got in the ssh window:

This output appears every time the "next-song" button does not work. When it does work, Canola simply reports going to the next song.

Hope this helps.