Your card is slipping out of the external socket, you need to push it in a bit further you havent actually locked it in yet. it should click into place and to get it out you wil have to push it in again and it will pop out.
In the file manager set up a folder on your card for music.

As far as players go there are several to choose from sterling, yamp, streamtunner, xmms, canola, kagu, kilikali, ukmp, mplayer and several gui front ends for it (kmplayer, smplayer, etc.).Each have different levels of gui interface with canola being one of the most sophisticated and yamp being one of the least.


hope that helps