I followed the procedures for Creating an Amazon EBS-Backed Linux AMI with the exception that I did not shut down the original instance, just let AWS reboot it.
When I launch & start a new instance, I consistently cannot connect via SSH (or any method for that matter). I can connect to the original instance with no problems, even after reboots.
The new instances are in the same availability zone, in the same security group, and have the same key-pair as the original instance.
I don't think it matters, but the original instance was a
m1.medium, and I'm trying to launch a