Character prop alignment in preview window

My character was created with 3d Max 9 and animated with biped. Its armor and weapon props are separate objects linked to the biped with helper objects.

When I import my .fbx to Unity, everything works as expected except the preview window shows the character in root pose (the same pose as biped's "Figure Mode") while the props are offset on the vertical axis, rotated 90degrees, and oriented correctly for the first frame of the selected animation.

It looks like Unity is using biped to correctly position all the non-skinned linked objects, but keeping the skinned character mesh in its root pose for some reason. Once I place the character in the scene, everything works fine, it's just that the preview is all messed up.

Has anyone seen or solved this issue?