You have edited your index.php so instead of blank.png being loaded, it is your logo which is suppose to be generate in template_css.css by
img#logo {
background:transparent url(../images/logo.png) no-repeat scroll 0pt;
float:left;
height:138px;
margin-left:38px;
width:469px;
}
Therefore, change the index.php logo image to blank.png and alter the above reference to your logo