为什么验证返回此错误。如何解决？
ul#navigation li#navigation-3 a.current
值错误：背景位置太多值或无法识别值：-164px -164px -36px -164px -164px -36px
这是错误屏幕。
替代文字 http://shup.com/Shup/321632/110323115458-My-Desktop.png
CSS
ul#navigation { height: 36px; left: 300px; list-style-image: none; list-style-position: outside; list-style-type: none; position: relative; top: 74px; width: 603px; }
ul#navigation li { display: inline; }
ul#navigation li a { height: 36px; float: left; text-decoration: none; }
ul#navigation li a:link, ul#navigation li a:visited {font-family:Arial; color:#595959; font-size:1.1em; font-weight:bold }
ul#navigation li a:hover, ul#navigation li a:active {color:#404040}
ul#navigation li a span { display:block;
float:left;
padding-left:8px;
padding-top:14px;}
ul#navigation li#navigation-1 a { width: 53px; background: url(../images/menu-sprite.jpg) no-repeat 0px 0; }
ul#navigation li#navigation-1 a:active, ul#navigation li#navigation-1 a:hover { background-position: 0px -36px; }
ul#navigation li#navigation-1 a.current { background-position: 0px 0px -36px; }
ul#navigation li#navigation-2 a { width: 111px; background: url(../images/menu-sprite.jpg) no-repeat -53px 0; }
ul#navigation li#navigation-2 a:active, ul#navigation li#navigation-2 a:hover { background-position: -53px -36px; }
ul#navigation li#navigation-2 a.current { background-position: -53px -53px -36px; }
ul#navigation li#navigation-3 a { width: 78px; background: url(../images/menu-sprite.jpg) no-repeat -164px 0; }
ul#navigation li#navigation-3 a:active, ul#navigation li#navigation-3 a:hover { background-position: -164px -36px; }
ul#navigation li#navigation-3 a.current { background-position: -164px -164px -36px; }
ul#navigation li#navigation-4 a { width: 100px; background: url(../images/menu-sprite.jpg) no-repeat -242px 0; }
ul#navigation li#navigation-4 a:active, ul#navigation li#navigation-4 a:hover { background-position: -242px -36px; }
ul#navigation li#navigation-4 a.current { background-position: -242px -242px -36px; }
ul#navigation li#navigation-5 a { width: 88px; background: url(../images/menu-sprite.jpg) no-repeat -342px 0; }
ul#navigation li#navigation-5 a:active, ul#navigation li#navigation-5 a:hover { background-position: -342px -36px; }
ul#navigation li#navigation-5 a.current { background-position: -342px -342px -36px; }
ul#navigation li#navigation-6 a { width: 96px; background: url(../images/menu-sprite.jpg) no-repeat -430px 0; }
ul#navigation li#navigation-6 a:active, ul#navigation li#navigation-6 a:hover { background-position: -430px -36px; }
ul#navigation li#navigation-6 a.current { background-position: -430px -430px -36px; }
ul#navigation li#navigation-7 a { width: 77px; background: url(../images/menu-sprite.jpg) no-repeat -526px 0; }
ul#navigation li#navigation-7 a:active, ul#navigation li#navigation-7 a:hover { background-position: -526px -36px; }
ul#navigation li#navigation-7 a.current { background-position: -526px -526px -36px; }