display: inline-block

According to http://www.w3.org/TR/CSS2/visuren.html, "inline-block" is a
valid CSS value for the "display" property. However, when validating my page
(http://jigsaw.w3.org/css-validator/validator?profile=css2
<http://jigsaw.w3.org/css-validator/validator?profile=css2&warning=2&uri=htt
p%3a%2f%2flithorien.net%2fblog%2findex.shtml>
&warning=2&uri=http%3a%2f%2flithorien.net%2fblog%2findex.shtml
specifically), I am told that "inline-block" isn't valid CSS. Per the spec,
the validator is incorrect in this behavior.