Nokia 6230

I transferred some mp3 files into the MMC using the Nokia PC Suite and have been trying to play the songs but the songs cant be played? How do I make mp3 songs to play??

Also when I try to delete the songs from the MMC it tells me "Unable to delete".
Does anyone have any clue abt what is going on and how do I correct these problems?

Any kind of help will be appreciated.

Thanks.