Absolutely positioned, non-replaced elements

Please see <http://paginas.fe.up.pt/~ei02043/opt/absoluteposfloatedchild.xhtml>
and <http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width>

left, width and right for the div are 'auto' so the following should be applied:

margin-left: 0;
margin-right: 0;
left: 8px; ( from margin-left of parent, which is the body in this case )
width: auto;

Then, for rule #3, since width and right are auto and left is not, the
width is shrink-to-fit.

However, then it says to "solve for right" and that's where I'm not
sure what should happen.

Gecko and IE end up calculating right as 0 and since it does that,
both left and right are not auto and a width is defined, which causes
the div to span across the page.
Opera ends up calculating right as auto so the div is still just fit-to-width.

Now, I think the float: right; for the child h3 causes IE and Gecko to
get 0 for right, but I'm not 100% sure how.

Can someone explain if Gecko and IE are correct and if so, how
*exactly* 'right' ends up being 0 for them.

Thanks

-- 
burnout426