Urgent CSS issue in Safari! *****

A site I recently wrapped up was working great in all browsers, and for some
reason I hopped on Safari today and noticed it's not formatting right at all!
I'm not sure where the issue is as it was hunkey dorey before, and am hoping
somebody on here might know so I can fix it quickly before there are complaints
from people browsing to the site.

http://www.mackinnonicehorse.com

Anybody have any ideas? If you look at it in other browsers you'll see how the
navigation should be, and there are some other small CSS issues in Safari that
I'm seeing. It was working fine though? ideas? Please help!