9/X Script Editor confusion

Apologies if this is already well known. I’ve just discovered an interesting consequence of having OS X and OS 9 on the same disk. When I’m working in 9, it’s no longer possible to open 9’s Script Editor by creator ID - that is, by double-clicking a script file or by using a script that mentions ‘application file id “ToyS”’. The system tries to open X’s editor instead, resulting in a delightful, partially gobbledy-gook error message.

There’s no problem if 9’s Script Editor has already been opened by file path. Current processes apparently take precedence over the Desktop File when it comes to the owners of creator ID’s.