IMovie Effect Blanks Screen When Applied

Question

I have followed the directions below to apply an effect to part of a clip. When I preview the effect, it looks fine. After I apply the effect it blanks out the section where the effect has been applied and there's no sound either. Your help would be greatly appreciated. I've tried this many time with different effects and I get the same results.
To apply a video effect to a clip:
1. Select the clip or clips you want to alter.
To apply an effect to a section of a clip, drag the crop markers to select the frame range you want.
2. Click the Effects button and select a video effect.
You see a sample of the effect in the preview monitor at the top of the Effects pane.
3. Move the Effect In and Effect Out sliders to indicate when you want the effect to begin and end.
Tip: when you drag the Effect in or Effect Out sliders, you see the times appear in the preview window. You can click the numbers and change them to adjust the timing.
4. Adjust the effect with any other available sliders (some effects have more options).
5. Click Preview to view the effect in the iMovie monitor.
6. Repeat any of the above steps until you have the effect the way you want it.
7. Click Apply.

Answer 1

Try this way just to see if there is some other problem:
Cut your clip on the time line using the cursor for your in and out points that you want to apply the effect to. Use apple T to cut where the cursor is for the start of your effect and move the cursor to the end point of your effect and use apple T again. Click on the the clip between the to points you have cut. It should be blue. Hit apply on the effect tab and play the clip. It should have worked if it didn't post back.
Hope this helps.