After there has been a timeout on my ssh connection (e.g., left the ssh session running and closed my laptop), it is very difficult to re-login with ssh. I keep getting an ssh timeout error. I tried removing the hostname from the known_host file (per a friend's suggestion) which sometimes helps, but other times doesn't -- and I dont know why

This is in connection to accessing my EC2 instance on Amazon.

This is driving me nuts -- any help, much appreciated.