Yesterday while writing the code of an add-in for a new article I was calling Form.ShowDialog() without passing the owner window and I noticed that clicking the Visual Studio button on the Windows 7 taskbar, I got the modal form hidden behind the Visual Studio window (I had to click Alt+Tab to get the it back). Today I have been unable to reproduce this problem on another computer with Windows 7, but the other computer still reproduces it. Anyway, I already knew how to fix this problem for good, so I have documented it in this new article:

HOWTO: Show a modal form from a Visual Studio .NET add-in
http://www.mztools.com/articles/2011/MZ2011014.aspx