You may want to post about this problem in the Canola forum. The Canola developers are unlikely to find this thread.

This won't help you: I experienced what appears to be the same problem with iTunes-created AAC files when I tried out an older version of Canola. The files played fine in Media player, but Canola didn't even detect their existence. I sent one or two sample files to Handful to test, but I haven't followed Canola's development since, so I don't know if the issue has been listed as fixed.