Animationst not smooth

Im having a problem getting smooth movement in my animations. My first frame of my main movie contains alot of my clips so the 1st frame is 70k. Could that be the problem why some of the animations are jumpy (menus are not quick to snap on roll overs)…its built at 18fps. The final will be delived on a DVD to a client-so I was unsure if I can use a higher frame rate. (not sure of the speed of the computers that will be viewing later so I didnt want to make to intense).
Thanks in advance for the suggestions.

I am really trying too emulate the transitions (quick response and smoothness) as seen in