Ubuntu :: System Freeze During Upgrade?

I'm putting this in general, because I'm not sure if many of the specifics are relevant.I have an everex cloudbook which I purchased from eBay with hardy herron on it.I finally got around, today (I've had it for a year), to installing netbook remix 9.10 with a usb key I had also purchased from eBay.Now, during the upgrade (using update manager) from 9.10 to 10.04, the system appears to have frozen.(desktop frozen, no response to keyboard or mouse).Now, I'm not sure if something could still be happening inside there, and if it would be a good idea to let the machine site overnight before rebooting it. Frankly, it happened once already, and I rebooted, and update manager just took up where it left off once I logged in.

I have not determined what's causing these freezes. It's not a new machine, of course (everex, afaik, doesn't even exist now), so maybe netbook-remix is too taxing on the hardware? I installed xfce to get away from the bloated netbook-remix graphical menu garbage, which did seem to allow the system to run faster. Anyway, the real question here is, while the interface appears frozen, could the upgrade still be developing under the surface? (I hear a fan running in there. There is no hdd to spin, but flash memory, so I don't know if the fan is any indication of internal activity). Would you wait to reboot it? (update mgr indicated 4 hrs remaining to upgrade, in the installing upgrades phase, not downloading, appears it froze during "Running post-installation trigger install-info"). Or just reboot it and see what happens (get update mgr to start again?)? The system never froze on me with hardy. It was pretty quick and snappy, in fact.