Drawing in Illustrator using shift on Mac SUT problem

I am using Illustrator CS3 on Mac and PC.
I need to perform an operation where I hold shift to create a box.

The script is very simple.

Typetext “\s”

MoveTo (790,150)
MouseButtondown 1
MoveTo (720,250)
MouseButtonUp 1

Typetext "\S"

This works fine on Vista however with 10.4.10 I can’t get shift to work with this specific operation. It works fine in other occasions like uppercase type. However when I attempt to use shift in live mode to create a shape with shift it will not work. Drawing objects be it a straight line or constrained shape will just not work in live mode or in script.

Has anyone had this problem?