AppleScript - "Where is System Events"

[Ian Wood]

Sometimes I need to find out what applications are currently running  
on a Mac, and I've been using the following code to get a list:

put "tell application" && quote & "System Events" && quote & "to get  
name of every process" into tS
do ts as applescript

This normally returns an AppleScript list of application names, but  
I've had a couple of people complaining that they are getting prompted  
to choose an application with the warning "Where is System Events".

Anyone have any clues?

Ian