This is (just one reason) why you should use explicit imports from modules. Don't import INFINITE from Win32::ChangeNotify unless you actually use that. My guess if you've got another module that is importing INFINITE before you implicitly asked Win32::ChangeNotify to import it. But it may not be easy to find what that other module is if you used implicit imports.

Though, exports -- which module exports are used? can likely help, here. It can also help you change your implicit imports to explicit imports so you actually know and document what is being imported from where when you look at a particular file of Perl code.