Rounded Box

<div class="boxcontainer">
  <div class="t"><div class="b"><div class="l"><div class="r">
     <div class="bl"><div class="br"><div class="tl"><div class="tr">
        <div class="boxlabel">{LABEL}</div>
        <div class="boxcontent">{CONTENT}</div>
     </div></div></div></div>
  </div></div></div></div> 
</div>

.t {background: url(/images/dot.jpg) 0 0 repeat-x;}
.b {background: url(/images/dot.jpg) 0 100% repeat-x;}
.l {background: url(/images/dot.jpg) 0 0 repeat-y;}
.r {background: url(/images/dot.jpg) 100% 0 repeat-y;}
.bl {background: url(/images/bl.jpg) 0 100% no-repeat;}
.br {background: url(/images/br.jpg) 100% 100% no-repeat;}
.tl {background: url(/images/tl.jpg) 0 0 no-repeat;}
.tr {background: url(/images/tr.jpg) 100% 0 no-repeat; padding: 5px;} 

.boxlabel {
   float:left;
   display:inline;
   position:relative;
   top:-5px;
   left:5px;
   padding: 0px 2px 0px 2px;
   background-color:#FFFFFF;
   color:#1E90FF;
   font-size:10;
   font-family: Arial;
}

.boxcontent {
   position:relative;
   top:-5px;
   text-align: left;
}

.boxcontainer {
   margin: 5px;
}

The boxlabel float left with relative/top/left position to adjust its position. And its background-color is set to make the background opaque, otherwise, it is transparent and the below border line is shown.

Also, note that we have a padding on the last img div, to avoid text inside the box overlap with image.

See: CSS and Round Corners: Build Boxes with Curves

CSS Hack

 * html div.tableContainer { /* IE only hack */
     width:95%;
     border:1px solid #ccc;
     height: 285px;
     overflow-x:hidden;
     overflow-y: auto;
  }


* html div.tableContainer table thead tr td,
* html div.tableContainer table thead tr th{
 /* IE Only hacks */
   position:relative;
      top:expression(dojo.html.getFirstAncestorByTag(this,'table').parentNode.scrollTop);
  }

html>body tbody.scrollContent {
    height: 262px;
   overflow-x:hidden;
   overflow-y: auto;
  }

 tbody.scrollContent td, tbody.scrollContent tr td {
     background: #FFF;
     padding: 2px;
  }

  tbody.scrollContent tr.alternateRow td {
     background: #e3edfa;
     padding: 2px;
  }


<div class="tableContainer">
<table dojoType="SortableTable" widgetId="testTable" headClass="fixedHeader" tbodyClass="scrollContent" ...>
   <thead>

It is excerpted from dojo sortableTable test file, since IE doesn't support overflow(scrollbar) on tbody, it plays a trick by wrapping a scrollable div around table, and relatively position the thead to simulate the effect.

* html only visible to IE, and child selector html>body not visible to IE. Also note that the descendant selector is applied above.