Pantheon Desktop compiled... but does not work correctly

[Azimoth]

Hi,

I installed Pantheon following the Gentoo-Wiki Guide using layman.

Basically:

1. layman -a elementary
2. Ensure that X USE flag is included in the system's global USE flags.
3. emerge --ask pantheon-base/pantheon-shell
Let Portage take care of keywords, use flags etc.
4. emerge --ask pantheon-base/pantheon-shell
5. Done.

Now I can select "Pantheon" as a desktop environment at the login screen, yet there's only the "dock" at the bottom, the rest of the screen is black and my curser remains a "X".
The autostarting programs do show up, but they have no "window frame", no menu, no "minimize/maximize/close".
Somewhere in between there is a message that no system tray is found.

Gnome continues to work fine. Any idea how to fix this?
What further information would you need to help me?

PS: All Pantheon related posts I found were about compilation errors, hence I started this one. If there's an older post dealing with this, I would be thankful for any hint.

[DawgG]