this is actually one of those crazy browser problems that I see all the time. I took a look at your code and made some changes to make it work perfectly and I was going to email it to you, but you won't allow that. But here's what I did... this should help everyone else out as well:
First, I got rid of all Height tags that had percentages as their values. IE will take percentage of available space and Safari uses percentage of space on the page. That's why the Safari render is so much further down.
Next, got rid of your left and right gutter columns until all I was left with is your content. Next I wrapped your content in a table like so:
[html]<table width=100% height=100%><tr><td align=center valign=middle>
<! --- ALL YOUR CONTENT GOES HERE -->
</td></tr></table>[/html]
Then IE & Safari both see that height=100% as the total height of the page.
Also, I got rid of your duplicate <body> tag.
Hope that helps you and others.
Mark Armstrong
Development Lead
MailChimp