A export problem with the skin animation

God for the exporter of 3dmax 8.0,i have made this schematic like this:(with a human model animation that bend his waist by skin modifier and with three LOD level person128(with skin modifier) person64 and person32(with multiRes modifier).when export it that has no error,but input it to the showtool that has a strange thing happen like picture 2 and the lower level can not match the animation)
if i unlink the person128 which has the skin modifier ,that work good but the detail is missing.