Can't even OPEN iMovie

Something seems to have happened to my iMovie since the last time I used it a few days ago. Now, when I try to open iMovie it keeps circling through the same drop down menu regardless of what I select! Here's what happens: I dbl click on iMovie icon in the Applications file, the "Welcome to iMove" screen appears with a three choice menu and if I select "Open Existing Project" none of my DV files are accessible. Yet, when I select "Create Project" then enter new name, click save, it goes right back to the first three choices,(Open Existing Project, Quit or Create Project).

A few days ago, when in iMovie trying to import DV files it gave me messages that my files were too large, that they had to be < 2 GB. Yet, now that i've trimmed the file to 1.2 GB I can't even access it! What is up with this???

I have not deliberately made changes to iMovie. I've used Streamclip to trim the original into DV. I added Apple Playback Component to my HD as well as Perian, so why can't I even OPEN iMovie??? One thing I did do, was trash unwanted files in an effort to get more HD space, but if I'd accidently trashed a working component of iMovie wouldn't it alert me???

Thanks in advance to those of you willing to help me. I'd be really lost without you! ~G

You might want to quit iMovie and trash its Prefs.

com.apple.iMovie.plist

--ken