Apple's screensaver applescript has an error

For some reason, running the script below causes keys F8-F11 to be disabled, among other problems like disabling cmd+` (change windows in safari) and also cmd+tab (change apps).

From second script at the bottom of the page:
http://www.apple.com/applescript/bluetooth/system.html

Toggle Screen Saver – This script will start and stop the screen saver. Note that it will not force the screen saver to quit if it requires a password.

try
tell application “System Events”
set the process_flag to (exists process “ScreenSaverEngine”)
end tell
if the process_flag is true then
ignoring application responses
tell application “ScreenSaverEngine” to quit
end ignoring
else
set the target_app to ((path to “dlib” from system domain as string) & ¬
“Frameworks:ScreenSaver.framework:Versions:A:Resources:ScreenSaverEngine.app”) as alias
tell application (target_app as string) to launch
end if
on error
beep
end try

Does anyone know how to fix this problem? It’s really annoying not being able to use Synergy’s keyboard commands to pause/play iTunes after I trigger the screensaver.

Thanks,

-Bill