I switched desktop systems from Ubuntu 10.04, first swapped to xubuntu-desktop, then performed the LTS upgrade to 12.04.
A couple of systems have a text mode boot time splash / progress verses the Xubuntu usual graphical progress screen. When these systems finish booting, the proper Xubuntu graphical login screen appears, and from there it is normal.
I have verified that grub is still configured thusly:
and performed another update-grub, without change.
Is there some package that perhaps got left off during either the swap over to xubuntu-desktop, or in the LTS upgrade which is responsible for the boot time graphical display?
All systems have nVidia video chips, and all use the binary nVidia drivers. So that is not a difference between systems.