Form Icon in project manager

When having a form in a project, opossed to a plain cpp file, the project
managar shows an icon with a form in the lower left. Also you can expand
from the icon, showing the cpp file icon and the form icon respectively.
I'm having a form in  a project, but the manager don't show the form icon.
However, I can open the CPP file and then pressing F12 (toggle form/unit)
will bring up the form..

Anyone who knows how to get the form icon back?