StuffIt, like a few other programs, is not fully compatible with MultiFinder 6.0. If you've used StuffIt under MultiFinder, you've probably noticed that it will not open its own documents when the program is already active and you've double-clicked on a StuffIt file on the desktop. The reason for this is that MultiFinder 6.0 uses a trick to get applications to open their files. It does this by finding the owning application, looking for a menu in the application whose title item is "File" and then looking for "Open" or "Open…" in that menu. Then it activates the application, sends that menu event to it, intercepts the Open File dialog, and inserts the file name you double-clicked on. Whew!
Unfortunately, StuffIt's menu item is "Open Archive…" which won't be recognized, and you can't fix it by changing StuffIt's File menu resource - it doesn't have one. But there is a workaround which is described in Apple's Tech Note #205:
MultiFinder will first look in the application's resource fork for a mstr or mst# resource which contains an alternate menu item to be used. In StuffIt's case, it needs an mstr #103 resource containing the string "Open Archive…".
I've included that resource in this file as "sit.fix.rsrc". Just paste it into StuffIt with ResEdit and StuffIt will respond normally to MultiFinder's file-opening tricks.
But wait! StuffIt also creates segment files! Well, that's another problem. Since they're in a different menu you have to choose to have StuffIt respond to .sit file openings or .seg file openings. I can't find a way to get it to do both. If, for some reason, you'd prefer to fix StuffIt for .seg files, use the resources in the "seg.fix.rsrc" file instead.
Once installed, those annoying "Some StuffIt documents could not be opened or printed" messages should be (mostly) a thing of the past.
