Computer does not show MP3 player as connected and how to stop a song playing

If you installed the firmware update, you might have forgotten to change the device to MSC mode.. try going to settings>USB mode>MSC

This should probably work..

to stop a song while its playing, click the |<< button while you have the screen with the current song. (you can pause a song on this same screen with the >|| button) If you have gone back to any of the menu screens, wait for a couple seconds and the player will automatically go back tot he song display screen so you can stop the song.