Help playlists all disappear when I transfer new songs


Hi there. i am using galaxy mini 2 and enjoying it.
now i have a problem with the playlists. they keep disappearing whenever i transfer new songs. i use microSD card for my songs. the songs and all other files are still there. its just the playlists that keep disappearing. i am frustrated because it takes 2 hours to set up my playlists. I just use the stock gingerbread music player, i did not root the phone. please help.