A new iMovie means a new blog! Come visit:
Unlocking iMovie '09 & '11

That's right, it's version 7.1.4. Don't ask me what happened to 7.1.3. I guess it never reported for duty.

According to Apple, "This update addresses general compatibility issues, improves overall stability, and addresses a number of other minor issues."

It looks like this update at least changes all the references for ".Mac" to "MobileMe," logos and all. 

Anyway, you can get yourself this new update via your Software Update, or use the following link:

iMovie 7.1.4 Standalone Updater