Form App as pre-build step

I created a simple form app with VS2008. Just a Windows Forms Application from the template and F6 to build it. This app runs fine from VS2008 or from windows explorer, but when I run it as a pre-build step in a dsp IDE, the app actually starts, but doesn't become visible. However, when I perform a MessageBox.Show(""); in my Form1 class constructor, then Form1 does become visible after clicking ok on the messagebox :confused: Does anyone have an idea what might be causing this ?