Not enough space?

http://wp1130551.wp169.webpack.hosteurope.de/Sites/Tests/test/drupal-6.8...

Look this website...

CSS File (important parts only):

/* Globale Einstellungen */

body {
	background-color: #000000;
	color: #FFFFFF;
	font-family: Arial,"Trebuchet MS",Verdana;
	font-size: 90%;
	margin: 0;
	padding: 0;
}

/* Seiteneinstellungen */

#page {
	background-color: #262626;
	margin: auto;
	width: 1200px;
	border: #191919 solid;
	border-width: 0 10px 0 10px;
}

/* Sidebars auf 20% Breite setzen */

#sidebar-left, #sidebar-right {
	width: 180px;
	float: left;
	padding-left: 5px;
	padding-right: 5px;
}

/* Seitenkopfeinstellungen */

#header {
	height: 175px;
	text-align: center;
}

#name-and-slogan {
	margin-top: -20px;
}

#redplain {
	position: absolute;
	background-color: #990000;
	width: 840px;
	height: 175px;
	/*left: 220px;*/
	float: left;
	border-left: 10px #660000 solid;
	border-right: 10px #660000 solid;
	padding-left: 10px;
	padding-right: 10px;
}

/* Einstellungen Haupt */

#main {
	border: #222222 solid;
	border-width: 10px 10px 0 10px;
	float: left;
	width: 800px;
	padding-left: 5px;
	padding-right: 5px;
	background-color: #333333;
}

/* Einstellungen Links */
a:link {
	color: #FFDDDD;
	text-decoration: none;
}

a:visited {
	color: #FFFFFF;
	text-decoration: none;
}

a:active {
	color: #FFFFFF;
	text-decoration: none;
}

a:hover {
	color: #FF0000;
	text-decoration: underline;
}

/* Einstellungen Primary */

#primary {
	float: left;
	width: 22.5%;
	margin-left: -24.5%;
	padding-left: 10px;
}

#primary a {
	width: 15%;
	display: block;
	height: 22px;
	font-size: 0.9em;
	color: #ffffff;
	padding: 5px 85% 0 5px;
	text-align: left;
	text-decoration: none;
	margin-top: -70px;
}

#primary a:hover {
	border-left: 10px solid #444444;
	border-right: 10px solid #770000;
	background: #393939;
	margin-left: -10px;
}

/* Einstellungen Secondary */

#secondary {
	float: left;
	width: 15%;
	margin: 0;
	padding-right: 10px;
}

#secondary a {
	width: 15%;
	display: block;
	height: 22px;
	font-size: 0.9em;
	color: #ffffff;
	padding: 5px 100% 0 5px;
	text-align: left;
	text-decoration: none;
	margin-top: -70px;
}

#secondary a:hover {
	border-left: 10px solid #444444;
	border-right: 10px solid #770000;
	background: #393939;
	margin-left: -10px;
}

I thought very long about it, but I just don't understand why the right sidebar (beginning with "Primary Links") slips below the first one (which means it has not enough horizantal space I think). Can somebody explain me?
Thank you!
fortuneNext