Since installing Leopard, I'm having trouble using Play Sound in an AppleScript that's called in a Rule for Microsoft Entourage.

The error I receive is "doesn't understand the "

The script:

set cusrPath to (path to "cusr" as string)

set soundAlias to (cusrPath & "Documents:Microsoft User Data:Custom Sounds:Quack.aiff") as alias

tell application "Play Sound"
play (soundAlias as alias)
end tell

I'm also having trouble opening scripts in the Script Editor in Leopard. SE crashes when I try to open a script.

I rely on Play Sound and the ability it has given me to get custom notifications for email. What do I need to do to get it working again?