The Vixen profile file has not been required by xLights. However, starting with version 2011c (coming soon), if you use a Vixen profile, you will be required to copy it into your xLights directory.
If you are having problems with the audio, what happens when you are on the playlist tab, select a row by clicking on the row number, then click the "Play item" button?
Also, what version of Windows are you using?
Matt