Normal use of Mp3Tag, with default settings after first install. After succesful update to the tags, a modal dialog prohibits you from defining the next task until you close it. This dialog box can be disabled, but if you do there is no notification at all.
Unless an error occured the program did exactly what the user expected it to do. There is no reason to interrupt the user workflow.
When no error occured, drop the modal dialog box in favour of a non-interrupting means of user notification. A good way would be to show a message panel at the bottom of the main folder listview for a few seconds. Kind of like the way the MSN Messenger event popup works, but instead, dock it in the main application window rather than raising it in the lower right corner of the desktop.
Here is an example of what I have in mind, about halfway down the page.