NEED HELP EXPORTING INTO DIVX FILE!

[noni_mus]

i'm trying to export my video as a divx avi file, which i made in imovie (i'm not sure if that changes anything, but please read on). my main problem is that the end result is choppy. unfortunately, i can't change it's 720 x 576 size, but i already changed the framerate to 60.00 and the avg. bitrate is 2100. i'm thinking it's the max keyframe interval that i need to tweak, but i've been playing w/ it so far and the exported file is still a lil choppy and later in the video the music goes out of sync =\ so please, DOES ANYONE KNOW HOW TO HELP ME?!???