css - Why won't the padding go away? -

i have been stumped on coding mybb theme. first off there seems constant padding around entire container. firefox used identify , container reading screen 1583 wide while screen in actuality 1,600. has padding height well. seems whenever adjust width smaller width weighted left. don't want floating left.

http://img689.imageshack.us/img689/4378/3xeu.png

in photo provided have container, , body set 100% width. menu seems go past because said width of 9,000px wide. refuses go more left.

it's margin, not padding, it's set in browsers default in body tag, add css:

body{margin:0}