Just one of those CSS annoying problem that related to DOCTYPE.
http://developer.mozilla.org/en/docs/Images,_Tables,_and_Mysterious_Gaps
Spent good few hours scratching my head on this, I know I should have looked at the DOCTYPE generated by my editor (Eclipse Aptana) on the first instance, but I didn’t.
And what makes it even worse, I don’t actually need to put any DOCTYPE at all as I was developing HTML for email newsletter. Sigh.