Thanks for taking the time to reply. I'm just getting started on this so I have a learning curve. If I copy on the system.img, it boots fine, but if I copy both system.img and userdata.img then it does not boot. My userdata.img (built on my machine) is only 5 MB, whereas the one in the iDroid 1.0.3 release is 1004MB. Something in my build flags maybe?
Androids build system reduces the size of the images it creates to their bare minimums (as this speeds up flashing them to actual android phones) as such our images have to be manually resized after creation.
When I have some time, I'll post up a post build script for you that does this