Did you set your phone to USB mass storage mode?
I took a card out of my LG and just stuck it in my new krave and after i told it to scan for music it found all of the songs.
If setting phone to usb mass storage doesn't let the computer recognize the card, get a card reader.
put the songs on the card that way and tell the phone to scan to find music on card. I don't know if this phone requires things to be in specifically named folders the way my LG EnV did, but the computer wouldn't recognize that phone either so I used the card reader and made the folder myself and put the music in manually and then the EnV read it.
Hope that helps. I've only had my krave for 8 hours now so I haven't had more time to play.