Unable to login to Gnome session after installing lxde
 

On my Ubuntu 9.04 netbook remix I installed lxde window manager. After login in with lxde I'm unable to login to a gnom session.
All I get is an empty background image and no menus or toolbars.

Only way is to log in with lxde, wich starts lxde and gnome in a kind of combination.

Is there a way to easily restore a sane set och config-files for a gnome-session without deleteing them all and loosing all settings?

I ran gnome-panel and got the menu back, but there are still problems. All window decorations are gone as well as ability to move and resize windows.
Seems like the window manager is either missing or not running. Any ideas?