Sometimes when you make some mistake in an app, like forgetting to enter a subject for email, you get these popups warning of the problem. Then you have to click OK to dismiss the popup and correct the error.
What I would like to see is for the app to also be checking the error condition that caused the problem, and if it gets corrected, take the popup down automatically. Of course this also means the app developer would have to learn about multithreading and how to put the popup...
