some objects refuse to scale in size when moved

Say I have three circles on a slide. I want to animate a move of each circle to another section of the slide and I want the circles to either shrink or grow as they move. I can do this with two of the circles with no problem, but the last one will only expand to a certain size. Try as I might, I can attempt to pull on the sizing corners all I want, but they literally just go away with each attempt and I'm left with a circle that will not budge in size. Anyone else having this problem with multiple object moves?