Howto remove the boarder on panel applets?

[Jonas Aaberg <cja gmx de>]

Hi!

Is there away to remove the one pixel wide boarder that is created around
all panel applets? It is somehow always gray, and when you've selected
the background colour to something else and the applet also adopts to
the background colour, this gray boarder is really annoying.
(Actually, it is one pixel black, one gray, one black and so on until
you click/select another applet.)

Has panel_applet_set_size_hints(...) something to do with this? 
I havn't found out any documentation nor comments in the source code
what this function really is supposed to do.

I use the Gnome-panel version 2.2.0.1

Best regards,
 Jonas