Thanks, GarryP, that's good to know, next time I will just try re-sizing in the palette itself.
The cmd key while dragging helped a lot, but it still didn't keep things 100% circular. Every time I would start out with exact values and after resizing (even pressing the cmd key before, after, or at the same time) it would be very close, but still slightly different in the decimal points. Fortunately I was shrinking most of them for an artistic look, so it was neither important nor noticeable that they weren't perfect circles.