Replying to Sony Vegas issue= won't import whole clip

Hey guys, I have sony vegas platinum 9 and for some reason it wont import the whole clip. I have a clip that is 50 seconds long and when i import it, it is only 30 seconds long! Where is the rest of the clip? I tried uploading it to vimeo, the whole clip played fine, and when i downloaded it and imported it in vegas it was still only 30 seconds long.
Has anyone had this same problem or know how to fix it?
Thanks for your help