iMovie fails to import H.264 properly

My new camcorder, a Samsung HMX-H105, uses "H.264 (MPEG4 part10/AVC)" according to the manual. My first test movie was filmed in 1080/50i. When I import in iMovie 8.0.2 using Full, the clip gets the wrong aspect ratio - it is too wide with black bars at the top and bottom in the preview, like every other line has been stripped.

If I move a clip into a project, the black bars go away but the image is still stretched (and cropped with material to the left and right missing). In the small 'filmstrip' previews, the frames are displayed correctly though.

If I plug the camera to the Mac using USB without starting iMovie, I can browse the camera SS drive and the recordings are visible as .MP4 files. These play with the correct aspect ratio in QT player. The interlacing is a lot more visible than I was expecting (but I'm totaly new to camcorders and this could be as it should be).

The files play fine on my PS3 - with less visible interlacing, I'm telling myself.

I suspect that there is something about the files created by the Samsung that iMovie doesn't like.

Is it common for imports that are supposed to be H.264 to fail in iMovie?

Is there a tool out there that I can use to inspect the files in detail, maybe compare with a file from another H.264 camera that is known to work with iMovie?

Any help from you guys on this would be very much appreciated by me!

/jonas