Button image is lost (???)

Hi all,

I have a DLL project in C# that has a dialog with a few controls, one of
which is a button. The dialog has its own custom icon (stored in the
dialog's resx file.) This shows up fine.

I'm trying to assign a gif file to the Image property of the button using
the form designer - select the Image property, click the ellipsis (...)
button, select Local resources in the "Select Resource" dialog and then
click the Import... button to select the image file. When I hit Ok on the
dialog, the selected image appears on the button and when I save it, the
image gets saved into the resx file. Yet, when I close and reopen the dialog
in the designer, the image is gone. (It's still in the resx file.)

Am I missing something here or is this a bug?

Thanks a lot,
Gyorgy Bozoki