I just installed WordPress 3.5.2 on an Amazon Linux AMI EC2 micro instance. When I tried to install the wp-db-backup plugin (Plugins -> Add New), I was prompted for a Hostname, FTP Username, FTP Password and Connection Type.
The answer to this question recommended that passwd be done at the comm...
OK, I see. It looks like WordPress don't have permissions to create new files in the system. Do you have access to the server configuration, or is this a shared hosting?