jameshopkins - 9:22 am on Jul 9, 2009 (gmt 0)

The :enabled and :disabled UI pseudo classes aren't part of CSS 2.1 - they were introduced in CSS 3.

Does it make a difference if you swap the two?

IE8 is handling the parsing of this selector correctly; as SuzyUK has verified, your suggestion won't many any difference.

CSS error parsing rules for declaration blocks states, "When a user agent can't parse the selector (i.e., it is not valid CSS 2.1), it must ignore the selector and the following declaration block (if any) as well". Subsequently an unknown or invalid simple selector in a grouping selector (which is what SuzyUK posted) will cause the entire declaration to be dropped. I understand particularly in the instance of a grouping selector, this parsing behaviour may not always be intuitive to authors.