The Cancel Cancer

Few things in computer program usage irk me the way a broken/unresponsive cancel button does. When I click "cancel" in a dialog, the dialog should instantly respond (preferably by just going away) and all the resources/jobs should be finished/closed in the background. I understand that this can be a tricky feat to pull off in some cases, especially with long-running processes, atomic transactions which require some sort of rollback, or processes that require external communication (i/o or remote requests), but I believe that every effort should be made to create a compelling and responsive experience for your users.

• windows hardware manager...update/search for driver
• eclipse jobs framework
• many others that I meant to put here but don't have the time to go find

Know some other culprits?  List 'em below in the comments: