My apologies for not replying. In the end I got side-tracked, so haven't had a chance to revisit this.
epimeteo: I think it was just the Ubuntu iso's I was having problems with. I'll have a look at that bug report.
bodhi.zazen: I was creating an image and then attempting to install Ubuntu using the following commands:
I also tried creating an image using Qemulator.
qemu-img create -f qcow ubuntu.img 5G
qemu -localtime -cdrom /dev/cdrom -m 512 -boot d ubuntu.img
aysiu: Yeah, I have used VirtualBox and quite liked it. However at the time, I was looking for a fully open-source virtualisation app and the VirtualBox deb I'd downloaded from the website wasn't. Of course I hadn't realised that the repos now contain VirtualBox OSE!
Anyway, when I have the time maybe I'll come back to this ...now it's the challenge that keeps me interested!