Scanning my collection results in 98 tracks found, when I have several thousand tracks, mostly mp3, that Amarok is not finding. The right folder is definitely ticked in Amarok settings, I've tried restarting Amarok and the whole computer, and rescanning the folder, and still don't find more than those few tracks, apparently random. What else can I do to investigate, so that Amarok can find and play the rest of my music?

What version of Amarok are you using?

The latest one packaged with Kubuntu 12.04, I believe, whichever that is.

If you run Amarok from the terminal with amarok --nofork --debug, is any useful information emitted when you order a full rescan (settings > configure Amarok > collection > full rescan)? Do you get any errors if you run the collection scanner from the terminal on one of the subfolders that isn't showing up, with amarokcollectionscanner /path/to/folder? (The expected output here is XML data listing the tracks in the folder you specified.)

Bizarrely, I ran Amarok in that mode, and it showed all the tracks, despite not having rescanned (though I do have it on auto-scan). The debug info showed it grabbing a load of stuff from Magnatune, but not XML. It looks like it just decided to start behaving because I posted in the forums. Thanks for your help, anyway.