from the moment you need to use position:absolute; why not use the left and right properties instead of padding?
HTML
<div style="height:73px;position:absolute;left:413px;right:413px;"><div style="width:100%; height:73px; background:url(top-fill-small.png);border:1px solid red">Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content </div></div>
Example: http://jsbin.com/anega3
change
alternative, if you need to use registration badly, you can set left:0; right:0; left:0; right:0; , and then use the existing paddings.
HTML
<div style="height:73px;position:absolute;left:0;right:0px;padding-left:413px;padding-right:413px;"><div style="width:100%; height:73px; background:url(top-fill-small.png);border:1px solid red">Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content Content </div></div>
Example: http://jsbin.com/anega3/2
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