ubuntu minimul - xfce4 problem

[Ben Edwards]

I am trying to get Ubuntu working on a laptop with a PII 233 and 128MB
RAM, 3GB HD.

I have installed Ubuntu Server (for a minimal install) and added xfce4,
metacity, xorg, gdm and x-server-core.

gdm comes up OK but when I log in it brings up the gnome splash screen
and hangs after desktop icon appears on the splash screen.  

There was no options in the gdm screen to select xfce4.

An I missing something, how do I ensure xfce4 is the windows manager.

Regards,
Ben