Extra movie frames?

I'd never used iMovie before last week, so please forgive me for being out of the loop.

Is it normal for iMovie to add a couple of completely white frames at the end of every exported movie? If so, what's the recommended way to remove them? I tried everything I could think of yesterday with no success.

I guess if all else fails I can purchase a QuickTime license and just snip them out but that seems to sort of defeat the purpose of iMovie.