For a restyle of a website I had to change a lot of existing 'images' content parts to 'images <div>' contentparts. Normally when you select a different images contentpart all the previous selected images from the file center are gone and you have to select them manually again. Not a big deal but still time consuming.
I noticed by accident that if you first highlight the images and then change the contentpart, the images will still be there. I thought just share this with you, might be helpfull.