In the barrage of new email and such on all the lists about all this slicker-than-snot-on-a-doorknob AS stuff, I think I read a message from someone at Apple that there’s a setting you have to enable to make UI scripting work.
System Preferences → Universal Access
“Enable access for assistive devices”
That should do the trick, Greg. If it doesn’t, post again so I’ll know we need to dig deeper to play with our new toys!