The problem that was shown on the previous step seems mysterious. I've spent a lot of time browsing through VCL code with debugger and I have to say that I do not know the exact reason of this error. I've succeed in location of two boundaries - one before the error occurs and one after it. After several hours of work I've wrote a component that automatically fix this problem. Just drop it onto form surface and it will do all work for you. I've called it TsvSurviver.

This component protects the owner form and all it`s childs. In addition it protects all windows that use Application as their parent. These windows are: ShowMessage window, MessageDlg window, DB related dialogs and so on. The source code of modified example is available here (zip, 3kb). Test it and ensure that now all forms successfully survive logoff/logon.

Well, it is another checkpoint where this example could be finished. But I would like to discuss one more feature - detection of interactive user - and I suggest you to continue.