in your style.css, you have the following style:
.content .inner .about span {
color: #333333;
display: block;
font-family: Calibri,"Calibri Bold","Calibri Bold Italic","Calibri Italic";
font-size: 15px;
font-weight: bold;
line-height: 22px;
margin: 20px 0;
}
the margin: 20px 0; style is causing the problem. it is applying a 20px margin to the top and bottom of the info window.