This Wordpress site works fine in Firefox and Safari.
However viewing in Explorer 7 (don't care about 6) breaks the header/navigation area.
Weirdly enough, refreshing the page fixes the alignment issue, but then hides the header.
Any suggestions would be greatly appreciated.
The nav is positioned absolutely and IE7 usually behaves better when absolutely positioned elements have both vertical and horizontal values specified, so try setting the left style property to 0 as well. You'll also want to set the position of the wrap element to relative for this to work.
Additionally, setting the display of the nav to inline:block may help.
Alternatively, it may be something to do with SIFR, have you tried disabling SIFR as a test to see if this corrects the display?
I'd fix some code errors: [Invalid]Markup Validation of anothersideof.me - W3C Markup Validator. Scroll down in the validation report to see line numbers and source code.
And then look into the difference in doctypes: (SO link, as I didn't find a comprable link here at Doctype): What are the different doctypes in html and what do they mean? - Stack Overflow