I designing a theme for wordpress 2.3.1 on my site but I am having some weird problems. steveeller.com

1. When viewing in IE 7.0 the front page shows up but when you take one of the links in the "recent posts" it just goes to a blank page.

2. In IE 7.0 in my "recent posts" the posts are in a list, but you will see the type gets smaller as it goes down the list.

I am not sure if this is a css/xhtml problem or wordpress. I can view the site perfectly in FF, Flock, and Safari.

Can you help? Here is the CSS:

Code:
body, html {
	font-family:Arial, Helvetica, sans-serif;
	background-color:#343b48;
	margin: 0;
	padding: 0;
	text-align: center;
	color:#a3a6ac;
	height:100%;
}
img {
	border:none;
}
h1 {
	color:#ebe64f;
	text-transform:uppercase;
        font-size:18px;

}
h2 {
	color:#ebe64f;
	text-transform:uppercase;
	font-size:90%;

}
a, a:visited {
	color:#ebe64F;
	text-decoration:none;
	
}
a:hover {
	text-decoration:underline;

}
li {
	list-style:none;
	

}
ul {
	list-style:none;
	
}
.mainclass #container {
	
	width:800px;
	margin:0 auto;
	text-align:left;
	

}
.mainclass #header {
	height:91px;
	margin-top:20px;
	

}
.mainclass #headericon {
	float:left;
	background-image:url(images/tree.gif);
	background-repeat:no-repeat;
	width:100px;
	height:91px;
	padding-right:10px;

}
.mainclass #headerlogo {
	padding-top:35px;
	text-align:left;

}

.mainclass #rss {
	text-align:right;
	margin-top:-17px;
	font-size:75%;


}
.mainclass #rss a, .mainclass #rss a:visited {
	display:inline-block;        /* for all browsers except IE */
  	color:#a3a6ac;
  	text-decoration:none;
  

}
.mainclass #rss a:hover {
	display:inline-block;        /* for all browsers except IE */
  	color:#fff;
  	text-decoration:underline;
  

}
.headermenu {
margin:0;
text-align:left;
list-style-type:none;
text-transform:uppercase;
white-space:nowrap;    /* keep text on one line */
border-top-color: #a3a6ac;
border-bottom-color: #a3a6ac;
border-top-style: solid;
border-bottom-style: solid;
border-top-width:1px;
border-bottom-width: 1px;
margin-left:110px;
height:20px;
padding:0;
margin-top:5px;
}
.headermenu li {
font-size:90%;
float:left;
padding-right:25px;  	
}
.headermenu a {
text-decoration:none;
font-size:smaller;
color:#a3a6ac;
}
.headermenu a:hover {
color:#fff;
border-bottom-color: #ebe64f;
border-bottom-width: 2px;
border-bottom-style: solid;
}
.mainclass #clearfloat {
clear:both;

}
.mainclass #maincontent {
padding-top:20px;
overflow:auto;

}
.mainclass #columnleft {
	float:left;
	width:50%;

}
.mainclass #columnright {
	float:right;
	width:50%;
	text-align:right;
	background-image:url(images/recentbackground.jpg);
	background-repeat:no-repeat;
	width: 371px;
	height:270px;
	
}
.mainclass #posts {
	float:left;
    padding-left:20px;
   
	width:66%;
	margin:0;
}

.mainclass #sidebar {
	width:31%;
	float:right;
	text-align:left;
	height:100%;
	
}
.postbox {
	height:270px;
	width:80%;
	padding-left:20px;
	padding-right:20px;
	padding-top:30px;
	text-align:left;
}
.mainclass #footer {
text-align:center;
padding-top:20px;
font-size:85%;

}
.mainclass #page {
	float:left;
	width:100%;
	font-size:92%;
}
.mainclass #dsidebar li {
font-size:90%;
margin-left:-20px;
}
.mainclass #readpost a, .mainclass #readpost a:visited {
	display:inline-block;        /* for all browsers except IE */
  	color:#a3a6ac;
  	text-decoration:none;

}
.mainclass #readpost a:hover {
	display:inline-block;        /* for all browsers except IE */
	background-color:#ebe64f;
	color:#000;
  	text-decoration:none;