If a program is executed for the first time in Windows 7, it automatically hides the icon. Is there any manifest setting or option to force Windows 7 to always show the icon by default?
In .NET Rocks podcast, not long time ago, Kate Gregory from Microsoft was saying that it is impossible.
She said something like: "If user wants it (tray icon) he/she will put it there". Reason for this is to prevent mess in the tray area.