I have MTS files imported from a Canon HD cam. They import into I movie and I see them in the Finder folders and they preview fine. I have a new project and some of the clips are freezing and some audio is now gone? Do i need a file converter and convert

Question

I have MTS video files that import from a Canon Vixia HF S20 HD camera. I imported into I Movie. They converted into MOV files and I see them in the movies folder in finder. They view fine and run through the events folder in Finder. In I Movie, I created a new project and used a "Theme". The project worked fine at first but then some clips started to freeze and some lost audio. The effected clips are the same in the project library and in the event library, meaning they are froze in both places. As I said when i view through finder the MOV files preview and work fine.  Is this inherent to MTS files using in I movie. SHould i consider using a file converter to convert to MOV files prior to importing into I movie.
I found on Apple support site info that states the MTS files can only be imported through the camera. I am developing my back up procedures and now I am faced with backing up in the original MTS files but not being able to reload if necessary into I movie. Any suggestions?

Answer 1

I'd like to add that after I import these clips without thumbnails, iMovie does give me an error and say that they could not be imported. No explanation as to why, though. Again, they play fine on my camera.