[boo hoo]

I have a nokia, I was able to put music on the first time and now, when I go do it again it says that its connected in non compatible mode, what is with that?? how do I make it compatible have done all that it still comes back as been as incompatiable I have tried eveything nearly all day yesterday.. and still , I connect the usb to the phone it tells me to select I do media player and it does not work