Cannot import video into iMovie I have an avi file that takes 350mb; I go into iMovie and i create a new project, then i create a new event and then i click on import video, i go to the right directory, to the avi file and click on import. The import window disappear and appear a loading bar that says something like "Optimizing the video..." and in 1 second it disappear (... i don't see the bar load). Nothing else happens, but the video is not imported.
Why?

More informations

I tried to uncheck the optimization option but another loading bar appear saying "Loading video", when the bar is completed another bar appear and disappear immediately. It doesn't change anything: my video cannot be imported.

Some more try

Downloading Perian and Divx codec doesn't solve the problem.
I think your problem has something to do with not having the right Codecs (the bit of software that translates one type of video to another type). @Martin is right - if you can convert your video yourself you'll solve your problem, but it would be even better if you can teach iMovie to convert it for you. 

Try installing both Perian and DivX (I'm too new to post two hyperlinks, just Google DivX Mac - it's the top link) and then restart your computer - this will install extra codecs to allow you to covert between the different types of video.