sound prob

Hi all, i made a short anmation then added a wave sound, it works fine
but when i render the animation it has no sound .i whatched a vid on how
to add sound but it does not work for me . blender 2.72b
Any help on this as to what the settings should be .
Cheers Ralph.

Here a quick vid i made ,sound slightly off maybe ill sort it
please let me know what you think.