add min-width:315px;
to .poppy
http://fiddle.jshell.net/YxRvp/10/
#poppy {
position: absolute;
top: 200px;
left: 250px;
width: 315px;
height: 200px;
overflow: hidden;
background: #f9f9f9;
display: none;
z-index: 2;
min-width:315px;
}