Overflow box with width as length

Very old test case. First uploaded in around 2009. All values and bug as reported below are not applicable. All desktop browsers (Firefox, Chrome, Opera and IE10) show interopabilty.

Overflow box 'width' 400px

1a.
1b.
1c.

Containing block width =

Scrollable box 'width' 825px = ('margin-left' 25px + 'width' (400px x 200%)800px + 'margin-right' 25px~0px).

Overflow box 'width' 400px

2a.
2b.
2c.

Scrollable box 'width' 875px = ('margin-left' 25px + border-left-width 25px + 'width' (400px x 200%)800px + 'border-right-width' 25px + 'margin-right' 25px~0px).

Overflow box 'padding-left' + 'width' + 'padding-right' 500px

3a.
3b.
3c.

Gecko 1.8: Scrollable box 'width' 975px = 'padding-left' 50px + ('margin-left' 25px + border-left-width 25px + 'width' (400px x 200%)800px + 'border-right-width' 25px + 'margin-right' 25px~0px) + padding-right' 50px.

Gecko 1.9 & Safari 3: Scrollable box 'width' 925px = 'padding-left' 50px + ('margin-left' 25px + border-left-width 25px + 'width' (400px x 200%)800px + 'border-right-width' 25px + 'margin-right' 25px~0px) + padding-right' 50px~0px.

Opera 9.5: Scrollable box 'width' 1025px = 'padding-left' 50px + ('margin-left' 25px + border-left-width 25px + 'width' (400px x 200%)800px + 'border-right-width' 25px + 'margin-right' 25p) + padding-right' 50px + mystery 25px.

Overflow box 'border-left-width' + 'padding-left' + 'width' + 'padding-right' 525px

4a.
4b.
4c.

Opera 9.5: Scrollable box 'width' 1050px = 'padding-left' 50px + ('margin-left' 25px + border-left-width 25px + 'width' (400px x 200%)800px + 'border-right-width' 25px + 'margin-right' 25p) + padding-right' 50px + mystery 50px.

the extra 25px in Opera 9.5 is due to the 'border-left' of the overflow box. This does not happen with 'border-right'