http://bugs.winehq.org/show_bug.cgi?id=16486
--- Comment #5 from diafero@arcor.de 2009-06-23 13:44:44 --- Some additional observations regarding this bug: - It seems that after minimizing and restoring such a problematic application once, it actually has two windows: The normal one and an additional one with the same icon, size about 50x50 or 100x100 pixels, filled with garbage. When I use Alt-Tab I see both of them. Since I switched to KDE4, the main window is not always completely lost after minimizing, restoring and minimizing it again, by clicking the taskbar entry several times I sometimes get it back. Sometimes I also just get the small second window. - "Restoring" the application using a fullscreen 3D application does not work any longer with KDE4 - The 3d cover-flow-like alt-tab switcher if KDE4 sometimes completely crashes when switching to the strange second small window - I am not sure, but it could be that the common factor of all the applications is that they were built with Borland (Delphi or C++). I knows for sure that "Welt am Draht" is a Borland-application, I could try finding out about PlasmaShop and PRPTool.
My conclusion is that something the windows app does makes wine create a second window and tell the window manager strange things, which in turn leads to the weird effects I try to describe.