I just "apt-get --reinstall install"-ed libxine-extracodecs and it works fine. I'm closing the bug now.
** Changed in: amarok (Ubuntu) Status: Needs Info => Rejected -- [Dapper/Edgy] amaroK (1.3.9/1.4) refuses to play any playlist; just skips through https://launchpad.net/bugs/49344 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs