I suggest that you attempt to reproduce this issue. The steps to do so are completely available above. I would guess that you could do them entirely with your user instead of ~ubuntu-on-ec2.
regarding the difference in size, reproducibility is as easy as: On Lucid: $ bzr branch lp:~ubuntu-on-ec2/live-build/cloud-images
On Oneiric: $ bzr branch lp:~ubuntu-on-ec2/live-build/cloud-images
I suggest that you attempt to reproduce this issue.
The steps to do so are completely available above. I would guess that you could do them entirely with your user instead of ~ubuntu-on-ec2.
regarding the difference in size, reproducibility is as easy as:
On Lucid:
$ bzr branch lp:~ubuntu-on-ec2/live-build/cloud-images
On Oneiric:
$ bzr branch lp:~ubuntu-on-ec2/live-build/cloud-images