ive had problems (even still) with my memory card contents not showing up in media player although it would show up under file mgr. This happens sometimes, when i disconnect the n900 from the pc after its been in "mass storage" mode. Anyway i had to reboot N900. once i did that all apps would see contents of the card. If you havent formatted the card, remove any data you have stored on it, copy to pc, and reformat it. I formatted it with the phone but i assume u can use your pc too, but again, i let the n900 do it