I reckon using _ (underscore) in your classnames could be at least part of it. Replace them with - (dash) or another character and see how it does. this from: http://www.w3.org/TR/REC-CSS1#forward-compatible-parsing "in CSS1, selectors (element names, classes and IDs) can contain only the characters A-Z, 0-9, and Unicode characters 161-255, plus dash (-); they cannot start with a dash or a digit;" underscore is unicode cha 95.. so my take on this is that it's invalid in a selector. Sam