I've got a W800i, and that didn't work on mine. When I tried to do that it wouldn't play the song...I thought you had to use disc2phone to make it compatible for the phone to play.
I was talking about mp3s. Maybe I'll try again. Disc2phone is so slow!
Oh no I think I've realised the problem...I have the sony walkman on mine, so I don't think the files are compatible if you try and play them using the walkmen option. But if you just select the file by itself it might work.