If you create a script using the "Save As AppleScript" option in Soundtrack Pro's Audio Waveform Editor, and the script contains Japanese characters or has them in its filename, nothing will happen when you run the script from the Scripts menu in Soundtrack Pro.
You can remove the Japanese characters in a script using the AppleScript Script Editor. You can remove the Japanese characters in a script's file name in the Finder (the default location for AppleScript droplets saved from Soundtrack is ~/Library/Scripts/Soundtrack Pro Scripts/).