What could be causing import error?

I purchased a GoPro HERO helmet-mounted digital camera and connected it to my MacBook (OS X 10.5.8) with iMovie (7.1.4) using a USB cable.

The camera produces MP4 files which are visible in finder.

When I open iMovie it identifies and displays the movie clips for importing but at the end of the import process it says "An Error Occurred During Import" and the files are not finally imported. I tried numerous times, even importing one small clip at a time and get the same message.

There is no further information on what could be causing this.

The only way I managed to import these clips was to first copy them to my hard drive and then use the "Import movies" option in iMovie.

Anyone have ideas why I can't import directly from the camera?

Bill.