Comment 11 for bug 428692

Ross, The kernel you pointed at (ubuntu-kernels-testing-eu/ubuntu-karmic-i386-linux-image-2.6.31-302-ec2-v-2.6.31-302.7-ramdisk.img.manifest.xml) is not comparible to the kernel John loaded to ec2 US. It will not have ext4 in it.

That said, it *should* launch, as far as I can tell you should have launch permission, I even went ahead and re-ran the modify-image-attribute command to give it to all:
  ec2-modify-image-attribute --region eu-west-1 --launch-permission --add all ari-c45972b0

I believe this must be a bug in amazon's ec2-migrate-image. That command just must not work for kernel and ramdisk. I'll have to change my publish tools to only use migrate on images. Thank you for pointing this out.