Importing Clip with Alpha

I'm trying to import a clip from a stock library that is listed as having an Alpha channel.   When I play the clip outside of MC, it displays the standard checkerboard pattern that indicates an Alpha channel.  But when I import the clip into MC, an Alpha channel is not created on import.  The checkerboard is still displayed and editing the clip onto V2 does not result in a transparency in the checkerboarded areas.   I've tried every combination of import settings.  I've imported hundreds a Alpha channel graphics before, so I'm stumped...