when i inserted my memory card into my n900, it loaded up all the music and videos from it and they all played on my phone. I connected my phone to my computer to add more music but i think i disconnected it too early or something like that went wrong and now it wont play any of the music it just says "unable to play media, does not support media format". Im not sure how to get my phone to let me play the music or videos on my phone.