simple script stops working in 10.3.2

This script, which I have been using for a long time, suddenly has started giving me an “Apple Event has timed out message”:

tell application "Finder"
	set the visible of application process "Safari" to false
end tell

tell application "Digest Viewer"
	activate
end tell

No names have changed for the applications. I have similar scripts to quit Digest Viewer & launch Safari or Entourage and they aren’t working either.

Any suggestions?

that script ran perfect except i substituted digest viewer for firefox

Model: iBook
AppleScript: 1.9.3
Browser: Safari 312
Operating System: Mac OS X (10.3.9)