Cannot import MOD video clips into iMovie '09 from JVC Everio Camcorders

I am having an issue importing MOD video clips into iMovie '09 from various JVC Everio Camcorders.

I am using:

MAC OS X 10.5.8

iMovie '09 - version 8.0.6 (821)

The JVC Everio will be recognized by the Mac & by iMovie; iMovie will open the import video dialog box, and i can 'see' the video files on the camera. However, i cannot actually see what the video file is - i.e. the thumbnail is blank (this is not as it should be, and is the first sign of the problem).

If i select the clip and import it, the bar beneath the clip will fill up, and when full, it will tell me it has imported the clip. However, in the iMovie event that the clip was imported to, there is no video clip there.

On the Mac itself, if i navigate with Finder to where iMovie stores the event files, there will be a .MOV file there, which when played has audio but video. If it matters, i am using Quicktime Player Pro Version 7.7 (1680.25).

Also, i have been able to get these JVC Everios to work with this Mac in the past, but not for some time now. I am aware of workarounds using Handbrake and such, but i need for iMovie itself to be able to easily import the files directly from the cameras, as it should if working corrrectly. (i work in a school and all of the cameras & Macs are used by students, and the workarounds are just too complex and constricting for them to learn).

Finally, I have tried plugging the Everios via USB directly into the rear of the Mac, and had the camera's power supple plugged in, but still this doesn't work.

These are the JVC Everio Camcorders that i CANNOT import from:

GZ-MG130U

GZ-MG330HU

GZ-MS250BU

All files recorded in .MOD format

I CAN import from a Panasonic HDC-HS80

Files recorded in .MP4 format

I CAN import from a Panasonic AG-AC7P

Files recorded in .MTS format

It is not an issue with the JVC Everio Cameras, as I have no problem importing from all of the above cameras (JVC & Panasonic) into two other iMacs:

Mac OS X 10.7.4

iMovie '11 - version 9.0.4 (1635)

Mac OS X 10.6.8

iMovie '09 - version 8.0.6 (821)

Please help me out here! It's very frustrating that all the cameras work with the other Macs, just not this one!

Thanks so much in advance for any help you can offer!

Alan Buckler