Items being resized using the resize icons in the Alignment palette will be resized to the dimension of the object drawn first.
To reproduce the problem:
1) Draw a small rectangle and then a large rectangle.
2) Select both and hit one of the resize icons on the Alignment palette.
3) Note that the dimension used is that of the small rectangle. It was drawn first.
4) Undo.
5) Lock the small rectangle.
6) Select both and hit the resize icon.
ClarisImpact will beep and no resizing will occur.
There are no workarounds.