When I change the home directory of my Amazon EC2 instance from /home/ubuntu to /home/ubuntu/folder in the /etc/passwd file, I am no longer able to access the instance using my existing keypair. Once I switch it back to the original directory I have no problems and can log into my instance as normal. I have checked the permissions on the new folder and they are drwxr-xr-x, which is the same the /home/ubuntu folder. I have a number of instances running at the minute and because of this change I have no way of logging back into them to rectify the situation. Does anyone have an idea what is going on?

Thanks in advance