My two previous RPMs packages of Amarok (1.4.1 and 1.4.2beta1) for Mandriva 2006 were not able to play some files because of their file format. In a previous comment, Promeneur tell us that my 1.4.1 package was not able to play Mpeg2 files.

I myself experienced a similar problem: both 1.4.1 and 1.4.2beta1 were not able to play any of my Flac files. Apart the “There is no audio channel!” error message, I had no other information to help me track the bug.

Then I remembered that I was using PFL RPMs beside official Mandriva ones. So I updated plf-non-free and plf-free repositories. So I installed all packages whose name followed the “xine-_something_-1.1.1” pattern. Just after that Amarok was playing Flac files as expected!