I don't have an iphone to test (only the emulator) but it looks like the inline height you have in the anchor inside the h1 is not being applied.
<a class="brand" style="background: url('/templates/strapped/images/logo.png') no-repeat; width:327px; height:95px;" href="/"> Helps On The Way</a>
Try giving the height in the css in the media query for that log at the small width and see if it makes a difference. There's too much code for me to build a local demo to test I'm afraid.
I don't know if it will make any difference but worth a try.:)
Ralph's post also reminded me that webkit has a problem with scaling background images so you could also try -webkit-background-size:100%; in that inline style.