NOTE: This advice is very specific, and applies only to updating Spell Catcher X version 10.2, running on Mac OS X 10.4.x. Refer to our How do I Quit Spell Catcher? FAQ if you are using some other version of Spell Catcher X or Mac OS X.
Read this FAQ if you are updating Spell Catcher X 10.2.1.
There's really no reliable way to Quit the Spell Catcher X 10.2 application on Tiger - it will probably just re-open automatically right after quitting. You're going to have to choose a keyboard (flag) from the input menu, and log out and in again before you can update your copy.
It's important to be aware of the different way OS X 10.4 interacts with input methods. Even though you've chosen a keyboard in one app, it's quite possible that Spell Catcher's input method is still active in some other application, or even in some other document in the current application!