CSS Validator Parse Error

Hi there,
I've been using the W3 CSS Validator and for some reason it won't validate my CSS due to a parse error.The exact message is "Parse Error  height466px.The validator states that a curly brace { is causing the parse error however I have removed the entire rule and re-written it multiple times and the validator throws up the same error for the same line of my CSS every time, I can only assume it is detected some sort of invisible character or illegal UTF-8 character however I have no idea where this character could be coming from.
Kind Regards,George.