trouble importing dv to imovie

I was importing from my canon HV20 into imovie last night, and all was going well. I switched to a new tape this morning, shot at the same event with all the same settings, and now I cannot get the program to continue importing. The tape seems jumpy at first, and then it cuts off after about 3-4 seconds. I am not sure why this second tape won't import. I'd appreciate any help.

video plays in screen

Yes, the video plays fine through the screen, but it cuts out within 3-4 seconds once I click import.

Thank you

Thank you. I'll check both of those possibilities. I am trying again in a new project file--figured I could import and re-connect dv files later. I am also importing to an external hard drive this time and emptied my trash as well to see if the hard drive space was the issue. I appreciate your responsiveness.