lucy24 - 2:06 am on Nov 8, 2012 (gmt 0)
By "correctly" do you mean that it shows them at all?
The answer is almost certainly browser-specific.
I too got different results in both www preview (Webkit-based) and Camino ("Firefox Lite").
Apparently overflow is calculated differently for height and width. For height, <=101 px counts as overflow. For width it's <=100. You can see it clearly by setting the other property to 110 and just changing one.
:: will return to play around more, but no time now ::