Can't edit picture duration to photos already in timeline...

I am using Windows Movie Maker 2.1 on Windows XP Sp3. I have added some video clips and Images in the storyboard. While previewing I found the images running bit faster. Hence I went to options and changed the settings to increase the duration so that it runs slower. But the problem is this change is not effective for the already added images and clips. They are still running on the same speed, however the new images I’m adding to storyboard is running with the new speed.

So is it just me facing this problem or it is the working behavior of WMM? Do I need to remove everything and start it from beginning to get the new speed?

Nope, you dont need to restart it from beginning but instead you need to select all existing files, right click and change the duration. If you switch to Storyboard view and select all the clips as a batch...you can add the "Speed Up, Double" or "Slow Down, Half" effect to change the duration. Just select all the clips / right click the Effect and from the menu...choose...Add To Storyboard.