Table width in border-collapse: collapse model

Actual results: Seamonkey 1.x rv: 1.9a1 build 2005090305, Deer Park alpha 2 rv: 1.8b4 build 20050903 and DOM inspector report that the computed css width of the table is 300px and DOM inspector also reports that the table offsetWidth is 500px. Somehow, -moz-box-sizing is set to content-box and can not be set to border-box: computed style -moz-box-sizing stubbornly retains, maintains content-box. This webpage layout is related to bug 96463: border widths are subtracted from table's intrinsic width and bug 155955: [BC] outer half of collapsed table border bleeds out of table box (border-collapse)

Expected results: the reported computed css width of the table should be 500px and its offsetWidth should be 600px.

1^st col. & row	2^nd col. thead	3^rd col.	4^th col.	5^th col.
2^nd row	thead	abcd	abcd	abcd
5^th row	tfoot	a	b	c
3^rd row	tbody	abc	abc	abc
4^th row	tbody	ab	ab	ab

The relevant CSS code in that page is
body {margin: 15px 100px;} #idTable { border-collapse: collapse; border: 100px ridge lime; width: 500px; -moz-box-sizing: border-box !important; } td {border: 4px solid blue;}

Reference: CSS 2.1 Section 17.6.2 Border-collapse model says: "Note that in this model, the width of the table includes half the table border"