there seem to be many approaches these days for blocks with rounded corners.

there was one fully CSS version that draws one line rows along the top and bottom of the block with margins to give the rounded effect:

The rest use 2-4 images to get the effect

http://www.google.com/search?hl=en&q=rounded+corners+css&btnG=Google+Search&aq=f&oq=
rounded corners css - Google Search
http://www.cssjuice.com/25-rounded-corners-techniques-with-css/
25 Rounded Corners Techniques with CSS
http://www.spiffycorners.com/index.php?sc=contact&bg=ffffff&fg=001b2c&sz=5px
Spiffy Corners - Purely CSS Rounded Corners