Just to add to the list of people with a black screen on Internet install.
My install went ok till the point where it tried to "install" pluto-orbiter (packages were already installed). I end up with the same black screen on the core with white mouse pointer.
F7 doesn't do anything. Core appears fully functional otherwise, but I wouldn't trust it as being properly installed. I'm not sweating it at this point, as I'm just kicking the tires right now, and plan to burn it down and rebuild later as I'm sure I'll be making lots of mistakes as I poke around under the hood.
Host: Debian Sid/Squeeze Kernel 2.6.30-1-686-bigmem via KVM, AMD64 processor
Guest: KVM VM, default Cirrus Logic virtual graphics adapter, Kubuntu 8.10 install from CD, LinuxMCE install via Internet.
Installed via instructions here: http://wiki.linuxmce.org/index.php/LinuxMCE-0810_beta
problems occurred at the step ./mce-install.sh I didn't get the actual output, but it basically kept trying to install the pluto-orbiter package every 30 seconds.
Hope that helps!