sound versus speed problem

hi all. just gotten hold of r4, cant fault it! one little hitch though and i wonder if anyone can help me with it ??? im no programmer or computer buff so i realy need help/ right........ r4 runs sweet, real smooth and my pc isnt even that good, but it almost runs TOO good, if im playing some chill out tunes the scenes run almost double the speed of the music how do i slow it down or get it to run more in time iwth the music??????? any help would be great
cheers ppl
cheers ppl