I'm using Lumia 520, and I have an SDHC card.
I've noticed a strange thing. I managed to see the music in the built-in Music app after copying my MP3s to
[SDcard]/Music (or a subfolder), but only if I put the files there when the phone was on. The files that were already there (I used the SD card with my previous phone), are not visible (though they're visible also in my Win XP normally). Though the videos on the contrary are displayed in the Videos app.
Has someone experienced that? Is there some easier way than to delete files and copy them again?