Yeah, you can't change that layout, I'm afraid. You just have to work with it.
And here it the format I am after: http://twitter.com/RedCross
Ha ha, yes, that's the old layout (the other layout is a new feature). I'm pretty sure you can revert back to the old layout, if you want ... but it will require delving into the settings. I haven't updated mine to the new layout, so I can't experiment with going back to the old one at this stage. But in your Settings > Design, you could try just removing the header image and see if that reverts things back to the old layout.