[kNeo]

For future reference you can modify the height of the header by adding the following to additional.css:

#header {
height: 250px;
}

Change 250px to whatever number you want.

I think the vB team's goal here was to make it so the header automatically changed according to the size of the logo you used.

ps: you can add the code above to your own additional.css and then change your logo to be wider so people can click it to go back "home".

EDIT: full code to adjust height of header and make your clickable area wider:

#header {height:300px;}
.logo-image {width:450px;}