Stuck at the login screen

[Homer]

Fresh install of Kubuntu 10.04 LTS.

Machine is a microcomputer; an older version of this:
http://www.norhtec.com/products/mcjrmx/index.html

I successfully ran 8.04 on this machine in the past.  10.04 installs
without a hitch, but I'm stuck at the login screen.  Entering a
username/password the login process starts, but about 2/3 of the way
through the screen goes blank, and when it comes back I am again at
the login in screen.

Result is the same when choosing the failsafe option.