The vocals sound like they are flat... or more accurately, lacking sparkle. They sound totally different from the music.
The music, BTW is absolutely beautiful and the performance on the vocals is pretty decent.
Just my take..... personal opinion... the vocals need to be EQ'd to bring out the highs a bit more. It seems they are lacking that spaciousness and air that will make them sparkle and fit the music.
Others are having similar issues.... in this post for example>>>
http://forum.cakewalk.com/tm.aspx?m=2720372 Listen to the original for a minute or so...let her get to the chorus..... then drop down to post 10 and listen to the EQ'd version. I think you'll see or hear what I mean.