Version: (using KDE 4.2.1) OS: Linux Installed from: Unlisted Binary Package If tags of files in the collection are updated by an external program (e.g. EasyTag), Amarok doesn't automatically update it's collection. The collection only gets updated, if the filename is changed, too. Amarok 2.1 svn 20090308
What filesystem is your music on?
ext3 Also see http://amarok.kde.org/forum/index.php/topic,16628.0.html
Sorry, this is not a bug, but an artifact of how Amarok's collection works: Amarok notices changes in the collection by monitoring the _directory_ mtimes. So if you want a certain directory updated, you need to e.g. "touch" it (Unix command). If you write a new file to it, this will happen automatically, but not necessarily if you change an existing file, which leads to the situation you described.
I guess this one is somehow related to the same thing: https://bugs.kde.org/show_bug.cgi?id=186169