html - The most semantic way of making this container

Question

I want to make the following shape using divs and border radius, with fall back to square corners for old browsers. No images please.

I am having a bit of trouble making the bottom corner next to the title (highlighted with the red box). I don't want a lot of unnecessary divs, it has to be as simple and semantic as possible. alt text http://img715.imageshack.us/img715/4214/bradiuswut.gif

<div class="container">
   <div class="header">Title</div>
   <div class="body">Content</div>
</div>

.container{width: 660px; background: #fff;}
.container .header{float: left; width: 110px; background: #333; border-radius: 5px 5px 0 0;}
.container .body{clear: left; width: 660px; background: #333; border-radius: 0 0 5px 5px;}

Any ideas?

EDIT 1:

I did it like this: http://jsfiddle.net/a93Rb/16/

<div class="container">
    <div class="header"></div>
    <div class="headerspacer">
       <div class="headercorner"></div>
    </div>
    <div class="body"></div>
</div>

.container{width: 660px; background: #fff;}
.container .header{float: left; width: 110px; height: 30px; background: #333; border-radius: 10px 10px 0 0;}  
.container .headerspacer{float: left; position: relative; width: 550px; height: 30px; background: #333;} 
    .container .headerspacer .headercorner{ position: absolute; width: 550px; height: 30px; background: #fff; border-radius: 0 0 0 10px;} 
.container .body{clear: left; width: 660px; height: 100px; background: #333; border-radius: 0 0 10px 10px;}

EDIT 2:

I am going to use this method: http://jsfiddle.net/a93Rb/13/

I also found a method of using an image which will not appear if the browser does not support rounded corners. It is much more semantic, and the whole point of using border-radius is to negate unnecessary markup. I think I will actually use this method, but I won't accept it as an answer as I stated that I do not want images.

<div class="container">
    <div class="header"></div>
    <div class="body"></div>
</div> 

.container{width: 660px; background: #fff;}
.container .header{float: left; width: 110px; height: 30px; background: #333; border-radius: 10px 10px 0 0;}                                  
.container .header:after{content: url(http://img24.imageshack.us/img24/1112/corner0.gif); display: block; margin: 20px 0 0 110px;}
.container .body{clear: left; width: 660px; height: 100px; background: #333; border-radius: 0 0 10px 10px;}

Answer 1

As many suggested before, dark div with white div inside and border-radius on bottom-left corner. Example here.

The code is rough and should be rewritten, but it works. And you should synchronize div background color with page color.