AWS public key denied issue

I read this post:

AWS ssh access 'Permission denied (publickey)' issue

The information there is relevant, but does not help me solve my issue. I used to be able to login to my linux instance on AWS using ec2-user using the following command:

ssh -i key.pem ec2-user@[address].compute-1.amazonaws.com from my MacBook terminal

over the past few weeks, I'm getting this error now:

"Permission denied (publickey)."

I tried

ssh -v -i key.pem ec2-user@[address].compute-1.amazonaws.com from my MacBook terminal

and I get this output:

OpenSSH_5.2p1, OpenSSL 0.9.8r 8 Feb 2011
debug1: Reading configuration data /etc/ssh_config
debug1: Connecting to [address].compute-1.amazonaws.com 开发者_如何学Python[address] port 22.
debug1: Connection established.
debug1: identity file key.pem type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.2
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host '[address].compute-1.amazonaws.com' is known and matches the RSA host key.
debug1: Found key in [path]/.ssh/known_hosts:1
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: key.pem
debug1: read PEM private key done: type RSA
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
Permission denied (publickey).

Any advice on what's going on? How to get around this?

I have another user account on this instance that I previously created. I am able to login with that, and sudo into the root. I just cannot login with ec2-user anymore.

Thanks!

You may have to log in as root. If using a bitnami image, login as 'bitnami'

e.g. ssh -v -i key.pem bitnami@[address].compute-1.amazonaws.com