LG VX-8100

i dont know why but after i got the update i tried putting mp3s as a ringtone and my main screen goes black after a few minutes, i close the phone and open it again and its still black. i had to delete the mp3s because 1. they wouldnt play 2. they arent on my card 3. i lost my downloaded ringtones and had to get them back.so does anybody know whats going on.i show the mp3s on the card when i put it in the computer but when i put it back in the phone theres nothing there . what am i doing wrong. please help.