iChat AppleScript Event Error

I am trying to add an Apple Script to iChat that will cause the screen to flash with inverted colors when a buddy changes his/her status to "Available". Every time I set this up in iChat (Preferences>Alerts>Event>Buddy Becomes Available) and test it, I receive an error that states:

Event: Buddy Becomes Available
File: <name of script here>
Error: Error -1708

Picture: http://homepage.mac.com/delhux/.Public/iChaterror/iChat_scripterror.png
Script: http://homepage.mac.com/delhux/.Public/iChaterror/iChat_screenflash.scpt

I've tried trimming down the script, checking console, etc, etc and can't figure out why I get the error running the script through iChat, but not when running the script alone.

Anyone have any ideas? I'd really like to get this working...

Thanks,
-David