Re: So that explains it...
I have a Dell Mini 9 (1.6Ghz Atom single core, 1 Gb RAM, 8 GB disk) that ran perfectly well with Ubuntu LPIA. It cannot cope with current Ubuntu - somewhere around 12 something the UI just ground to a halt.
Installed Lubuntu and it works better than ever now. If just the file explorer application were a bit more friendly I would happily recommend Lubuntu.