A: 

I have never closely researched this, I just know buttons never do what they're told.

Is this what you mean? Explorer Windows and Mozilla bug - button box model

There is a Fix for Mozilla:

For Mozilla, add -moz-box-sizing: content-box to the button. Unfortunately this bug is unsolvable in Explorer.

Pekka  2010-02-22 09:13:58
I don't actually think you can call it *bug* - **every** browser (I actually test in latest FF, Op, Safari, Chrome and IE6/7/8) works the same... maybe there is some historical reason to it? as for - *buttons never do what they're told* - don't let me even start there :D
Adam Kiss  2010-02-22 09:17:19
It's most likely a limitation of whatever operating system you're using, which would explain the consistent results.
Rowno  2010-02-22 11:24:16

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