Command is not run when Enter is hit in a line comment with cursor on a last position in a file (no trailing spaces or newlines should go after cursor) for this keybinding:
{ "keys": "enter"], "command": "comments_aware_enter", "context":
{ "key": "selector", "operator": "equal", "operand": "comment.line" }
] },
Happens in both Sublime Text 2 and 3