I solve my problem but I think it is kind of lame solution.

First I installed the metacity packages. I took them out during my last remaster.

I first found on the 'net that I have to edit the /etc/xdg/lxsession/LXDE/config file to have the following.

[Session]
window_manager=metacity

This did not work, so another idea was to tweak the /etc/xdg/lxsession/LXDE/default and added "metacity --replace" to the bottom of the file. That did not work as well.

Finally I added the "@metacity --replace" in the /etc/xdg/lxsession/LXDE/autostart file and that did the trick.

Thanks!