iMovie Video FX

[RollTide]

Hey guys, Last night I was messing with iMovies and I wasnted to add a flash to one of the pictures in my movie/slideshow. I can look at the flash on the picture, and edit when it goes off, but the apply button is grayed out, and non-selectable. I was just wondering why this is, b/c I like what it looks like but I can't put it in the movie.

Also how do I make a song end where I want it to? For some reason the songs starts back up before it's actually over. I tried looking at help for these things, but no joy.

Thanks for the help guys.