this is kind of harder to answer,
you need to display the time slider then click on frame 1, key the blendshapes
then move on to frame 8 and key the blendshape to 1
then repeat this for the other shape but you have to key that start of the second one with the end of the first one
rendering - http://www.simplymaya.com/movie_page...html?tut_id=49
try that first
Thanks for wasting your time reading this line.